Section VI: Arrhythmias

HPI: Duration and severity of symptoms (palpitations, dyspnea, fatigue, lightheadedness, or syncope). Any history of atrial fibrillation and has cardioversion been attempted before.

PMH: Hyperthyroidism, hypertension, myocardial infarction, mitral stenosis.

Absent P waves, irregularly irregular R-R interval.

Figure 55–1

AFIB = Atrial FIBrillation.

RVR = Rapid Ventricular Rate: ventricular rate > 100 bpm.

HU = Hemodynamically Unstable: hypotension (systolic BP < 90 mm Hg) and evidence of shock (mental status changes or decreased urine output).

HS = Hemodynamically Stable: normotensive, normal mentation, no evidence of shock.

SDUR = Patient with AFIB < 48 hours (Short DURation). If unknown or doubt as to genuine duration, assume LDUR.

LDUR = Patient with AFIB > 48 hours (Long DURation) or unknown duration.

CDV = Direct current CarDioVersion.

EL-CDV = ELective CDV: There is time to plan for procedure including informed consent, monitored anesthesia care, and assessing for intracardiac thrombus. If AFIB is LDUR, obtain a transesopheageal echocardiogram prior to CDV. Abort CDV if any thrombus found and reassess after 3 weeks of anticoagulation.

EM-CDV = EMergent CDV: Performed to save the life of the patient at the risk of thromboembolism.

SAE = Search Alternate Etiology of shock: Being in AFIB with a normal ventricular rate does not cause shock.

FAIL-CDV = Patient has had CDV in past and reverted back into AFIB.

RC = Rate Control with goal of resting HR of 60–80 bpm, and < 110 bpm with mild exertion. For RVR, consider metoprolol 5 mg IV Q15 minutes (max 15 mg) or diltiazem IV bolus 0.25 mg/kg IV followed by 10 mg/hr IV infusion (titrate over the range of 5 to 15 mg/h IV for goal heart rate). For non-acute setting, consider metoprolol PO 25 to 100 mg twice daily or diltiazem 30 to 90 mg 3–4 times daily.

See chapter on anticoagulation for AFIB in all cases.

AFIB + RVR + HU = EM-CDV

AFIB + HU + (NO RVR) = SAE

AFIB + HS + (NO FAIL-CDV) = RC + EL-CDV

AFIB + HS + FAIL-CDV = RC

1. Wann LS, et al. 2011 ACCF/AHA/HRS focused update on the management of patients with atrial fibrillation (updating the 2006 guideline). Circulation. 2011;123:104–123.

2. Antonielli E, et al. Clinical value of left atrial appendage flow for prediction of long-term sinus rhythm maintenance in patients with nonvalvular atrial fibrillation. J Am Coll Cardiol. 2002;39:1443–1449.

HPI: Duration of symptoms (palpitations, dyspnea, fatigue, lightheadedness, or syncope).

PMH: Hyperthyroidism, hypertension, heart failure, mitral stenosis, stroke, transient ischemic attack (TIA), any thromboembolism from the heart (ex. to the mesenteric vasculature).

AFIB = Atrial FIBrillation.

CHADS2 = Score from 0–6 based on the patient's history:

• C Congestive heart failure [1 point]

• H Hypertension [1 point]

• A Age ≥ 75 years [1 point]

• D Diabetes mellitus [1 point]

• S2 Prior Stroke or TIA [2 points]

RAS = Risk factors Associated with Stroke = Prior stroke, TIA, thromboembolism, or mitral stenosis.

ASA = Aspirin 325 mg/day (if no contraindications).

AC = AntiCoagulation: Must ensure there is no significant contraindication to anticoagulation before initiating. Can use warfarin initiated at 5 mg/day and titrated to target INR of 2.0–3.0. Advantage of warfarin is inexpensive and disadvantage is it requires frequent follow up to adjust dose. Alternate therapy is dabigatran 150 mg twice daily. Advantage is it does not require checking for therapeutic level. Disadvantage is cost and cannot be used with prosthetic valves or significant valve disease, severe renal failure (Creatinine Clearance <15 mL/min) or advanced liver disease.

AFIB + CHADS2 < 2 + (NO RAS) = ASA

AFIB + CHADS2 < 2 + RAS = AC

AFIB + CHADS2 ≥ 2 = AC

The CHADS2 score is directly correlated with risk of stroke:

CHADS2 Score   Adjusted Stroke Rate (%/year)

0 (Low)       1.2–3.0

1–2 (Moderate)     2.8–4.0

3–6 (High)      5.9–18.2

1. Wann LS, et al. 2011 ACCF/AHA/HRS focused update on the management of patients with atrial fibrillation (updating the 2006 guideline). Circulation. 2011;123:104–123.

2. Fang MC, et al. The net clinical benefit of warfarin anticoagulation in atrial fibrillation. J Am Coll Cardiol. 2008;51(8):810–815.

3. Gage BF, et al. Selecting patients with atrial fibrillation for anticoagulation:Stroke risk stratification in patients taking aspirin. Circulation. 2004;110(16):2287–2292.

HPI: Palpitations, lightheadedness, dyspnea, syncope.

PMH: Congestive heart failure, myocardial infarction, rheumatic heart disease, hyperthyroidism, pericarditis.

PSH: Coronary artery bypass graft.

AFLUT = Patient diagnosed Atrial FLUTter on ECG of less than 48-hour duration.

HS = Hemodynamically Stable: patient not hypotensive, in cardiogenic shock, or displaying mental status changes.

HUSL = Hemodynamically UnStabLe: patient with hypotension, cardiogenic shock, mental status changes.

P-REV = Pharmacological REVersion with ibutilide (0.1 mg/kg over 10 minutes if patient < 60 kg or 1 mg over 10 minutes if patient >60 kg; if patient fails to revert to sinus rhythm, repeat dose again).

RC = Rate Control with goal of resting HR of 80 bpm and 110 bpm with moderate exercise. Administer metoprolol 5 mg IV Q5 minutes (max 15 mg) or digoxin 0.25 mg IV Q2 hours (max 1.5 mg) in patients with heart failure and no accessory pathway.

CDV = Refer patient for direct current CarDioVersion.

CHADS2 = See chapter "Should I start anticoagulation in my patient with AFIB?"

CATH-ABL = Refer patient for radio-frequency catheter ablation to prevent recurrence of atrial flutter.

AC = Oral AntiCoagulation with warfarin. Target INR of 2–3 and in patients with mechanical heart valves a target INR of 2.5–3.5.

ASA = Aspirin 325 mg/day orally.

Controlling rate:

AFLUT + HS = RC + P-REV

AFLUT + HUSL = CDV

Anticoagulation:

AFLUT + CHADS2 > = 2 = AC

AFLUT + CHADS2 < 2 = ASA

• – Ibutilide can cause QT-c prolongation, which can lead to torsades de pointes. Patients should be observed with continuous ECG monitoring for 4 hours or until QT-c has returned to baseline after being started on ibutilide.

• – Ibutilide reverts atrial flutter to normal sinus rhythm in approximately 60% of patients.

• – If patients are not well controlled with medications or extremely symptomatic, they can be referred for consideration for catheter ablation.

1. Wellens HJ. Contemporary management of atrial flutter. Circulation. 2002;106:649.

2. Singer DE, et al. Antithrombotic therapy in atrial fibrillation. Chest. 2008;133:546S.

3. Stambler BS, et al. Efficacy of intravenous ibutilide for rapid termination of atrial flutter. Circulation. 1996;94:1613–1621.

HPI: Syncope, exercise capacity.

PMH: Sudden cardiac arrest, ventricular tachycardia, syncope.

FH: Brugada syndrome, unexplained sudden death

SH: Male

MED: Cardiac sodium channel blocker [procainamide], calcium channel blocker [diltiazem], beta blocker [propanolol], tricyclic antidepressants [amitryptiline], selective serotonin reuptake inhibitor [fluoxetine].

Type I: Coved ST-segment elevation >=2 mm (0.2 mV) at J-point with negative T wave in >=2 right precordial leads (V1–V3).

Type II: Saddleback ST-elevation with a high takeoff ST elevation >=2 mm, a trough displaying >=1 mm ST elevation, and either a positive or biphasic T wave.

Type III: Saddleback or coved ST-segment elevation of <1 mm.

Right bundle branch block (RBBB) or incomplete RBBB.

BRUG = Patient diagnosed with BRUGada syndrome type I, II or III on ECG.

HRISK = Patient is High RISK for sudden cardiac death: Patient has had an episode of sudden cardiac death, documented malignant arrhythmia (ventricular tachycardia or ventricular fibrillation), or a strong clinical suspicion of having serious arrhythmias (syncope).

PREF = Patient PREFerence to have ICD: After careful discussion of risks versus benefits and taking into account special circumstances (such as a strong family history of sudden death), patients may opt for ICD as primary prevention.

MED-TX = Medical therapy: Start Quinidine bisulfate 300 mg po q6h to prevent deterioration into malignant arrhythmias.

ICD = Refer patient for placement of Implantable Cardioverter-Defibrillator.

BRUG = MED-TX

BRUG + HRISK = ICD

BRUG + PREF = ICD

• – Quinidine can prolong QT-c interval, which can lead to torsades de pointes, and should be monitored upon initiation of treatment.

• – Patients with Brugada syndrome and a history of syncope have a 2.5 times higher risk of sudden cardiac death than patients with no history of syncope.

1. Belhassen B, et al. Efficacy of quinidine in high-risk patients with Brugada syndrome. Circulation. 2004;110:1731–1737.

2. Epstein AE, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Circulation. 2008;117:e350.

HPI: Assess presence and severity of symptoms: syncope, lightheadedness, dyspnea, palpitations.

PMH: CAD, congestive heart failure, hypertension, hypersensitive carotid sinus syndrome.

FH: AV block

PSH: Catheter ablation.

MED: Calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide.

3-AVB = Patient diagnosed with 3rd degree AtrioVentricular Block on ECG.

BC = Significant bradycardia: ventricular rate < 55 bpm or periods of asystole > 3 seconds.

HU = Hemodynamically Unstable: hypotension (systolic BP < 90 mm Hg) and evidence of shock (mental status changes or decreased urine output).

HS = Hemodynamically Stable: normotensive, normal mentation, no evidence of shock.

TPM = Temporary pacemaker: Placed emergently. May use transcutaneous pacing pads or transvenous pacemaker.

T-REV = Treat REVersible cause of 3-AVB:

• – Stop medications that impair AV conduction (ex: calcium channel blockers, beta-blockers, digitalis, amiodarone, adenosine, quinidine, procainamide).

• – Correct electrolytes (esp. K, Ca, and Phos).

• – Evaluate and treat myocardial ischemia (see this chapter)

• – Reduce increased vagal tone (eg, treat abdominal pain).

PPM = Permanent pacemaker. Placed electively after 3-AVB persists after reversible causes are treated. Patient referred to electrophysiology for placement.

3-AVB + BC + HU = TPM + T-REV + PPM

3-AVB + BC + HS = T-REV + PPM

1. Epstein AE, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Circulation. 2008;117:e350.

HPI: Syncope, angina, heart failure.

PMH: CAD, congestive heart failure, hypertension, hypersensitive carotid sinus syndrome.

FH: AV block.

MED: Calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide.

2-AVB-1 = Patient diagnosed with 2nd degree AV Block type 1 on ECG.

REV = REVersible cause of 2-AVB-1 such as increased vagal tone (carotid massage producing asystole > 3 seconds), myocardial ischemia (stress echocardiogram), or drugs (calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide) that suppress atrioventricular conduction.

T-REV = If present, Treat REVersible cause of 2-AVB-1.

• – Increased vagal tone refer for pacemaker placement.

• – Myocardial ischemia, see chapter on positive stress test.

• – Discontinue medication (calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide) causing impaired AV conduction.

PM = Refer patient for PaceMaker placement.

SBC = Symptomatic BradyCardia: heart rate <55 bpm with syncope, lightheadedness, fatigue, or exercise intolerance.

ASYS-3 = Period of ASYStole lasting >3 seconds or escape rate <40 bpm.

EXER = 2-AVB-1 occurring during EXERcise in absence of myocardial ischemia.

V-40 = Ventricular rate >40 bpm with left ventricular dysfunction, cardiomegaly, or block below the AV node.

POST-MI = 2-AVB-1 occurring following Myocardial Infarction.

NMD = NeuroMuscular Diseases such as myotonic muscular dystrophy, or peroneal muscular atrophy.

ABL = 2-AVB-1 occurring after catheter ablation of AV-junction.

2-AVB-1 + REV = T-REV

2-AVB-1 + SBC = PM

2-AVB-1 + ASYS-3 = PM

2-AVB-1 + EXER = PM

2-AVB-1 + V-40 = PM

2-AVB-1 + POST-MI = PM

2-AVB-1 + NMD = PM

2-AVB-1 + ABL = PM

• – The distinction between type I and type II 2nd degree AV block cannot be made when there is a 2:1 block (every other beat is dropped) as there is no way to observe the PR prolongation.

1. Epstein AE, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Circulation. 2008;117:e350.

HPI: Syncope, angina, heart failure.

PMH: CAD, congestive heart failure, hypertension, hypersensitive carotid sinus syndrome.

FH: AV block.

MED: Calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide.

2-AVB-2 = Patient diagnosed with 2nd degree AV Block type 1 on ECG.

REV = REVersible cause of 2-AVB-2 such as increased vagal tone (carotid massage producing asystole >3 seconds), myocardial ischemia (stress echocardiogram), or drugs (calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide) that suppress atrioventricular conduction.

T-REV = If present, Treat REVersible cause of 2-AVB-2.

• – Increased vagal tone, refer for pacemaker placement.

• – Myocardial ischemia, see chapter on positive stress test.

• – Discontinue medication (calcium channel blockers, beta blockers, digitalis, amiodarone, adenosine, quinidine, procainamide) causing impaired AV conduction.

PM = Refer patient for PaceMaker placement.

SBC = Symptomatic BradyCardia: heart rate < 55 bpm with syncope, lightheadedness, fatigue, or exercise intolerance.

ASYS-3 = Period of ASYStole lasting >3 seconds or escape rate < 40 bpm.

EXER = 2-AVB-2 occurring during EXERcise in absence of myocardial ischemia.

V-40 = Ventricular rate > 40 bpm with left ventricular dysfunction, cardiomegaly, or block below the AV node.

POST-MI = 2-AVB-2 occurring following Myocardial Infarction.

NMD = NeuroMuscular Diseases such as myotonic muscular dystrophy or peroneal muscular atrophy.

ABL = 2-AVB-2 occurring after catheter ablation of AV junction.

2-AVB-2 + REV = T-REV

2-AVB-2 + SBC = PM

2-AVB-2 + ASYS-3 = PM

2-AVB-2 + EXER = PM

2-AVB-2 + V-40 = PM

2-AVB-2 + POST-MI = PM

2-AVB-2 + NMD = PM

2-AVB-2 + ABL = PM

• – AV block can be provoked by exercise and is most often due to disease in the His–Purkinje system.

1. Epstein AE, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Circulation. 2008;117:e350.

PMH: Coronary artery disease (CAD), hypertension, congestive heart failure (CHF), arrhythmias (heart block, supraventricular tachycardia, atrial fibrillation).

SH: Alcohol.

EB = Energy Beverage containing greater than 140 mg of caffeine per 16 ounces.

ATH = ATHlete = exercising most days of the year and involved in competitive athletic activities.

N-ATH = N-ATHlete = not exercising most days of the year and not involved in competitive athletic activities.

1-CAN-EB = Limit consumption of EB to <500 mL or 1 CAN/day. Do not mix EB with alcohol. Rehydrate with water after intense physical activity or exercise. Consult health professional if experience any side effects to EB.

AVOID = AVOID consumption of EB.

MED-COND = Patient with following MEDical CONDitions: hypertension, CAD, CHF, or history of arrhythmias.

CONS = CONSult physician before using EB.

ATH = AVOID

N-ATH = 1-CAN-EB

N-ATH + MED-COND = CONS

• – Adverse effects of caffeine typically manifest with ingestion higher than 200 mg; these include insomnia, nervousness, headache, tachycardia, arrhythmia, and nausea.

1. Higgins JP, et al. Energy beverages: content and safety. Mayo Clin Proc. 2010;85(11):1033–1041.

HPI: Muscle weakness beginning in legs and progressing to arms, paralysis.

PMH: Renal tubular acidosis, hypoaldosteronism, renal failure, diabetes.

LABS: Potassium > 5 mEq/L.

ECG-HYPERK = ECG changes with HYPERKalemia seen are tall-peaked T waves, shortened QT interval, progressive lengthening of the PR interval and QRS duration.

SUS-HYPERK = SUSpect HYPERKalemia based on ECG findings alone.

LAB-HYPERK = K >5 mEq/L.

HYPERK = Confirmed diagnosis of HYPERKalemia.

ECG-HYPERK = SUS-HYPERK

SUS-HYPERK + LAB-HYPERK = HYPERK

• – Hyperkalemia can lead to sinus bradycardia, sinus arrest, slow idioventricular rhythm, ventricular tachycardia, ventricular fibrillation, asystole.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

2. Mattu A, et al. Electrocardiographic manifestations of hyperkalemia. Am J Emerg Med. 2000 Oct;18(6):721–729.

HPI: Muscle weakness (classicly beginning in legs and progressing to arms), paralysis, tetany, dyspnea, nausea/vomiting.

PMH: Diarrhea, Conn's syndrome, hypomagnesemia.

MED: Loop diuretic [ex. furosemide], thiazide diuretic [ex. hydrochlorothiazide]

LABS: Potassium < 3 mEq/L

ECG: Depression of ST segment, decreased amplitude of T wave, U waves in V4-V6.

Figure 64–1

E-STD = ECG shows ST-segement Depression

E-DAMPTW = ECG shows Decreased AMPlitute of T Wave

E-UW = ECG shows U Wave (seen best in V4-V6)

SUS-HYPOK = SUSpect HYPOKalemia based on ECG findings alone. If seen, obtain serum potassium level unless ECG abnormalities are unchanged from prior ECG and potassium level was normal at that time.

LAB-HYPOK = plasma potassium (K) < 3.5 mEq/L.

HYPOK = confirmed diagnosis of HYPOKalemia.

E-STD + E-DAMPTW + E-UW = SUS-HYPOK

LAB-HYPOK = HYPOK

• – Hypokalemia can lead to rhabdomyolysis as potassium release from muscle cells normally mediates vasodilation and increased blood flow to muscles during exercise; decreased potassium leads to a decreased blood flow to muscles during exercise.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

2. Shintani S, et al. Marked hypokalemic rhabdomyolysis with myoglobinuria due to diuretic treatment. Eur Neurol. 1991;31(6):396–398.

HPI: Constipation, muscle weakness, fatigue, confusion, polyuria, polydypsia, dehydration, nausea.

PMH: Hyperparathyroidism, malignancy, chronic kidney disease, nephrolithiasis.

LABS: Calcium >11 mEq/L.

ECG-HIGH-CA = ECG changes with HIGH CAlcium seen are shortened QT interval, PR prolongation, upstroke of initial portion of T-wave, increased amplitude of QRS, biphasic T waves.

HYPER-C = HYPERCalcemia.

LAB-HI-CA = LAB showing HIgh CAlcium level (> 11 mEq/L).

• – Chronic hypercalcemia may lead to deposition of calcium in heart valves, coronary arteries, and myocardium, resulting in hypertension and cardiomyopathy.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: Tetany, seizure, anxiety.

PMH: Hypoparathyroidism, vitamin D deficiency or resistance, chronic renal failure.

PSH: Head and neck surgery (thyroidectomy).

LABS: Calcium < 9 mg/dL.

ECG-HYPOCA = ECG changes seen with low calcium or HYPOCAlcemia are prolonged QT interval (> 0.45 seconds in males and > 0.47 seconds in females).

SUS-HYPOCA = SUSpect HYPOCAlcemia based on ECG findings alone.

LAB-HYPOCA = LAB showing HYPOCAlcemia, ie, calcium < 9 mg/dL.

HYPOCA = Confirmed diagnosis of HYPOCAlcemia.

ECG-HYPOCA = SUS-HYPOCA

SUS-HYPOCA + LAB-HYPOCA = HYPOCA

• – Torsades de pointes can be triggered by hypocalcemia due to prolongation of QT interval.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: Dyspnea, cough, chest pain.

PMH: Right ventricular hypertrophy, cor pulmonale, hypertension, coronary artery disease.

PSH: Right heart catheter insertion.

ECG: QRS duration >0.12 seconds, qRS or qrS in lead I and V6, ST depression and T-wave inversion in right precordial leads (V1–V3), ST-T vectors are discordant to terminal mean QRS spatial vector.

Figure 67–1

ECG-RB = QRS duration >0.12 seconds, qRS or qrS in lead I and V6, ST depression and T wave inversion in right precordial leads (V1–V3), ST-T vectors are discordant to terminal mean QRS spatial vector.

RBBB = Right Bundle Branch Block.

• – The left anterior descending artery is the major blood supply of the right bundle branch.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: May be asymptomatic, chest pain, dyspnea, palpitations.

PMH: Coronary artery disease, hypertension, heart failure, myocardial infarction.

ECG: QRS >0.12 seconds; loss of Q wave and wide slurred R wave in lead I, aVL, and v6; rS or QS in V1; ST depression and T wave inversion in V4–v6; ST elevation and upright T waves in right precordial leads (V1–V3).

Figure 68–1

WIDE-QRS = QRS > 0.12 sec;

R-CHANGE = Loss of Q wave and wide slurred R wave in lead I, aVL, and v6; rS or QS in V1;

ST-CHANGE = ST depression and T wave inversion in V4–v6; ST elevation and upright T waves in right precordial leads [V1–V3].

LBBB = Left Bundle Branch Block.

• – Left ventricular hypertrophy is commonly present alongside LBBB; however, it is difficult to diagnose ECG as LBBB produces similar changes. It is usually established by echocardiography.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: May be asymptomatic, dyspnea on exertion, chest pain

PMH: Hypertension, heart failure, coronary artery disease, aortic stenosis.

ECG: Left axis deviation; sum of S wave in V1 and R wave in V5 or V6 is > 35 mm; R wave in aVL is > 11 mm. S in V3 plus R in aVL is > 28 mm in men; S in V3 + R in aVL is 20 mm in women.

Figure 69–1

ECG-LV = Left axis deviation;

VOLT1 = VOLTage criteria #1: Sum of S wave in V1 and R wave in V5 or V6 is > 35 mm;

VOLT2 = VOLTage criteria #2: R wave in aVL is > 11 mm.

VOLT3 = VOLTage criteria #3: S in V3 plus R in aVL is > 28 mm (men) or > 20 mm (women).

LVH = Left Ventricular Hypertrophy.

ECG-LV + VOLT1 = LVH

ECG-LV + VOLT2 = LVH

ECG-LV + VOLT3 = LVH

• – LVH increases the risk of heart failure, ventricular arrhythmias, death following myocardial infarction, and a cerebrovascular event.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: Syncope, angina, heart failure.

PMH: CAD, congestive heart failure, hypertension, hypersensitive carotid sinus syndrome.

FH: AV block.

ECG: A general look at the ECG will often show a pattern of "grouped beating." Progressive PR interval prolongation followed by a nonconducted P wave.

Figure 70–1

E-PVAR = PR interval is variable and gradually increases from beat to beat, resets after a dropped beat.

E-PFAIL = ECG shows discernable P waves that fail to conduct to the ventricles (no QRS complaex tied to that P wave).

2-AVB-1 = 2nd degree AtrioVentricular Block Type 1.

• – The distinction between type I and type II 2nd degree AV block cannot be made when there is a 2:1 block (every other beat is dropped), as there is no way to observe the PR prolongation.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

2. Epstein AE, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Circulation. 2008;117:e350.

HPI: Syncope, angina, heart failure.

PMH: CAD, congestive heart failure, hypertension, hypersensitive carotid sinus syndrome.

FH: AV block.

ECG: A general look at the ECG will often show a pattern of "grouped beating." Prolonged PR interval of fixed duration followed by a P wave which fails to conduct to the ventricles, narrow QRS complex.

Figure 71–1

E-PFIX = ECG shows a fixed PR interval.

E-PFAIL = ECG shows discernable P waves that fail to conduct to the ventricles (no QRS complaex tied to that P wave).

2-AVB-2 = Second degree AtrioVentricular Block Type 2.

• – AV block can be provoked by exercise and is most often due to disease in the His–Purkinje system.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

2. Epstein AE, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. Circulation. 2008;117:e350.

HPI: Syncope, dizziness, dyspnea, palpitations.

PMH: CAD, congestive heart failure, hypertension, hypersensitive carotid sinus syndrome.

FH: AV block

PSH: Catheter ablation.

ECG: PR interval irregularly variable, dissociation between P wave and QRS, wide QRS complex.

Figure 72–1

E-PVAR = PR interval is variable.

E-DIS = No association (dissociation) between P waves and QRS complexes. The atrial rate (P-P interval) is often different than the ventricular rate (R-R interval). The QRS duration may be wide if there is a ventricular escape rhythm.

3-AVB = 3rd degree AtrioVentricular Block.

• – Third degree AV block occurring below the level of the bundle of His is typically associated with a narrow QRS complex.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: Chest pain, palpitations, fatigue, dizziness, syncope, hyperventilation; asymptomatic with ECG findings of PVC.

PMH: Hypertension, mitral valve prolapse, coronary artery disease, hypertrophic/dilated cardiomyopathy, heart failure.

SH: Caffeine, alcohol, smoking.

QRS duration >120 msec, bizarre QRS morphology, T wave in the opposite direction from the main QRS vector, fully compensatory pause.

Figure 73–1

PVC = Premature Ventricular Contraction present on ECG.

SYMP = SYMPtomatic patient experiencing chest pain, fatigue, syncope, hyperventilation.

ASYMP = ASYMPtomatic patient.

OBS = OBServe patient for development of symptoms.

PROP = PROPanolol 1 mg/dose every 2 minutes, maximum 5 mg.

AMIO = AMIOdarone 800 mg/day for 1 week.

PVC + ASYMP = OBS

PVC + SYMP = PROP + AMIO

Do not begin AMIO if:

• – Cardiogenic shock.

• – Severe sinus-node dysfunction causing marked sinus bradycardia.

• – Second or third degree atrioventricular block.

• – Episodes of bradycardia that have caused syncope (except when used in conjunction with a pacemaker).

• – Hypertension increases the prevalence of PVCs by 23%.

1. Zipes DP, et al. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death—Executive Summary. JACC. 2006;48(5):1064–1108.

2. Simpson RJ Jr. Prevalance of premature ventricular contractions in a population of African American and white men and women; the atherosclerosis risk in communities (ARIC). Am Heart J. 2002;143:535–540.

Most individuals are asymptomatic but also present with palpitations, dizziness, shortness of breath, and syncope.

A few patients can present with sudden cardiac arrest/death.

Delta wave (slurred upstroke of QRS).

Short PR interval and slightly widened QRS.

Positive r wave in V1 if pathway is between RA/RV, negative delta wave in V1 if pathway is between LA/LV.

Wide complex tachycardia if atrial fibrillation is present.

Figure 74–1

Evaluation

DE = If Delta wave disappears with Exercise.

DER = If Delta wave present during Rest and Exercise.

O = Observe.

EP = EP consult for programed electrical stimulation

Acute treatment

U = Unstable: if patient is tachycardic, hypotensive, altered mental status, and overall unstable.

DC = DC Cardioversion.

NCT = Patient has Narrow Complex Tachycardia.

AFRVR = If patient has Atrial Fibrillation with Rapid Ventricular Response.

TM = Terminating Maneuvers: first attempt valsalva/carotid massage, then if unsuccessful try adenosine/verapamil (5 mg q2 minutes up to 15 mg) or possible DC cardioversion if refractory.

ANT = ANTiarrhythmics: amiodarone or procainamide.

Chronic

SYM = If patient has episodes of SYMptomatic tachycardias, has high risk occupation (pilot, athlete), concurrent atrial fibrillation.

RFA = Radiofrequency Ablation.

ASMY = If patient is asymptomatic and <35 years.

ASMO = If patient is asymptomatic and >35 years.

EPS = EPS testing and risk stratification.

Evaluation:

• DE = O

• DER = EP

Acute treatment:

• U = DC

• NCT = TM

• AFRVR = ANT

Chronic treatment:

• SYM = RFA

• ASMY = EPS

• ASMO = O

1. Rosner MH, Brady WJ Jr, Kefer MP, Martin ML. Electrocardiography in the patient with the Wolff–Parkinson–White syndrome: diagnostic and initial therapeutic issues. Am J Emerg Med. 1999;17(7):705–714

2. Mehta D, Wafa S. Relative efficacy of various physical maneuvers in the termination of junctional tachycardia. Lancet 1988;1:1181

3. Belardinelli L, Linden J. The cardiac effects of adenosine. Prog Cardiovasc Dis. 1989;32:73

HPI: Syncope, angina, dyspnea, unresponsive

PMHx: Long-QT syndrome, heart failure, presence of defibrillator

Meds: QT prlonging drugs (See QTc chapter)

Rapid polymorphic ventricular tachycardia.

Prolonged QT.

Rotation of electrical axis.

Long and short RR intervals.

Figure 75–1

Figure 75–2

TdP = Torsade de Pointes is present on ECG or telemetry right now.

TERM-TdP = TERMinated Torsade de Pointes. May be self terminated or successful cardioversion.

RECUR-TdP = Recurrent TdP.

HU = Hemodynamically Unstable: hypotension (systolic BP < 90 mm Hg) and evidence of shock (mental status changes or decreased urine output).

HS = Hemodynamically Stable: normotensive, normal mentation, no evidence of shock.

EM-CDV = EMergent CDV: Performed to save the life of the patient.

INC-HR = INcrease Heart Rate. A faster heart rate decreases the QT interval and decreases the chance of TdP recurrenc. Can use isoproterenol 5 mcg/min or overdrive electrical pacing.

MED-TX = MEDical Treatment: Telemetry monitoring, replete electrolytes (especially magnesium and potassium, would give at least 2 gm magnesium sulfate empirically), stop QT prolonging drugs, rule out myocardial ischemia.

EP = ElectroPhysiology consultation. Patient should be evaluated for defibrillator placement and may need further evaluation for long-QT syndrome.

ARTIFACT = Occasionally motion of ECG leads will appear to be TdP such as when a patient is brushing teeth. Careful examination of the strips will reveal QRS complexes hidden in the artifact. If a patient is awake, talking, and pleasant, a careful review should be done to evaluate for artifact.

TdP + HU = EM-CDV

TERM-TdP + HS = MED-TX + EP

RECUR-TdP = INC-HR + MED-TX + EP

ARTIFACT = Reassurance

Torsades is associated with long QT syndrome that has characteristic PVC (R on T) phenomenon on ECG. It can be an inherited ion channel mutation or drug toxicity/electrolyte abnormality that affects conduction across certain ion channels.

Long-term management may include (1) ICD placement if avoiding offending agent does not work; (2) pacemaker if patient has bradycardia or AV block; (3) beta blockers (propranolol, esmolol, nadolol); and (4) sympathectomy.

TdP can be rapidly fatal and is an acute emergency.

The main treatment of TdP occurring right now is electric cardioversion.

TdP is strongly linked to long QT syndrome.

See QTc chapter for QT prolonging drugs.

1. Drew BJ, et al. Prevention of Torsade de Pointes in Hospital Settings. Circulation. 2010;121:1047–1060.

2. Hoshino K, et al. Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome. J Am Coll Nutr. 2004;23(5):497S–500S.

HPI: Asymptomatic or symptoms of palpitations, dizziness, dyspnea, syncope.

PMH: Long QT syndrome, atrial fibrillation.

ECG: PR interval <0.12 seconds; QRS >0.12 seconds; delta wave (slurred upstroke of QRS).

Figure 76–1

ECG-WPW = PR interval <0.12 seconds; QRS >0.12 seconds; delta wave (slurred upstroke of QRS).

WPW = Wolff–Parkinson–White syndrome.

• – Wolff–Parkinson–White syndrome is seen in 0.2% of the general population.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

2. Koplan BA, et al. ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery. Circulation. 2010;122:e480–e483.

HPI: Palpitations, dizziness, dyspnea, chest pain.

FH: AV nodal reentry tachycardia.

ECG: Ventricular rate between 120–220 beats/min; narrow QRS (< 0.12 seconds); P wave buried with or fused with QRS complex.

Figure 77–1

Figure 77–2

Figure 77–3

E-VR = ECG shows Ventricular Rate between 120–220 beats/min.

E-QRS = ECG shows narrow QRS [< 0.12 sec].

E-P = ECG shows P wave buried in or fused with QRS complex.

AVNRT = AtrioVentricular Nodal Reentry Tachycardia.

• – AVNRT occurs in approximately 10% of the general population and accounts for up to two-thirds of all cases of paroxysmal supraventricular tachycardia.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

2. Denes P, et al. Dual atrioventricular nodal pathways — A common electrophysiological response. Br Heart J. 1975;37:1069–1076.

HPI: Palpitations, syncope, chest pain, dyspnea.

PMH: syncope, history of sudden cardiac deaths, palpitations, tachycardia

FH: sudden cardiac death, prior genetic testing

AVRD = Arrhythmogenic Right Ventricular Dysplasia.

ECG-AVRD = QRS prolongation > 110msec in V1; prolongation of S-wave upstroke; Epsilon wave (distinct wave between end of QRS and onset of T wave); inverted T waves in right precordial leads (V1–V3).

• – ECG is normal in 40–50% of patients upon initial presentation.

1. Marcus FI, et al. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia. Circulation. 2010;121:1533.

2. Jaoude SA, et al. Progressive ECG changes in arrhythmogenic right ventricular dysplasia. Eur Heart J. 1996;17(11):1717–1722.

HPI: Palpitations, syncope, seizures, and/or cardiac arrest.

PMH: Congenital long QT syndrome (LQTS), bradycardia, atrial fibrillation, congestive heart failure.

MED: Amiodarone, digitalis (see chapter on drugs that prolong QT interval).

ECG: QT-c is the QT interval that is corrected for heart rate. QT-c = QT interval/(square root of RR interval). Prolonged QT-c interval is >0.44 seconds.

Figure 79–1

ECG-QT = QT-c >0.45 seconds in males and >0.47 seconds in females.

PROL-QT = PROLonged QT interval.

1. QT-c >0.5 seconds is high risk for torsade de pointes.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

HPI: Patient taking TCA (amitryptiline, imipramine, nortriptyline) with confusion, delirium, palpitations, hypotension, hyperthermia.

PMH: Depression, post-traumatic stress disorder, attention-deficit hyperactivity disorder, anxiety disorder.

ECG-TCA = ECG changes seen in TCA toxicity are prolongation of QRS >100 msec; deep slurred S waves in leads I and aVL; R wave in AVR >3 mm; R-to-S ratio in AVR >0.7.

TCA-TOX = TCA TOXicity.

• – Prolongation of QRS of >100 msec had a 26% of developing a seizure and those with a QRS >160 msec had a 50% chance of developing a ventricular arrhythmia.

1. Wagner GS. Marriotts Practical Electrocardiography. 10th ed. New York, NY: Lippincott Williams and Wilkins; 2000.

Identify the ECG patterns that can be mistaken as abnormal.

RSA = Respiratory Sinus Arrhythmia: change in R-R interval from respiration shortened during inspiration and prolonged during expiration, physiologic to match ventilation and perfusion.

VAGO = Pronounced VAGOtonia in athletes: sinus bradycardia, first degree AV blocks, supraventricular and ventricular ectopic beats. These do not require attention if they are asymptomatic or do not produce pauses greater than 4 seconds. Ectopic beats are no more frequent in athletes than the general population.

BER = Benign Early Repolarization: isolated J point elevation. ST/T ratio is < 0.25 and normalizes with isoproteronol or exercise (used to distinguish from pericarditis).

IRBBB = Incomplete Right Bundle Branch Blocks: QRS < 0.12 seconds, seen in patients with skeletal abnormalities.

PJTW = Persistent Juvenile T-Wave pattern: T-wave inversion in V1-3, but upright in other leads. The T vector is oriented left and posterior from heart orientation in chest. Seen also in potassium deficiency, vagotonia, hyperventilation.

PHT = Physiologic HyperTrophy: adaptation from static or dynamic exercise. Common variants are increased voltage, prominent U waves, intraventricular conduction delays, early repolarization, increased QT intervals.

PROM-T = PROMinent T-wave amplitude: T waves tall but not symmetric, seen in vagotonia, hyperkalemia, anemia.

STD = ST segment Depression: seen in excess sympathetic activity, hyperventilation, neurocirculatory asthenia.

QW = Q Waves: seen in vertical or horizontal heart/chest abnormalities/elderly. Lack of multiple leads with Q waves differentiates normal variants with old infarctions.

PRWP = Poor R-Wave Progression: differentiate old anterior MI with the presence of Q waves.

ASYM = ASYMptomatic patient.

SYM = SYMptomatic patient: patient who reports significant symptoms (especially with exercise), including chest pain, dyspnea, presyncope/syncope, or palpitations.

REASS = REASSure patient and tell them they likely have a normal variation on their ECG, and they should be fine; if they develop any symptoms, return for reevaluation.

ECHO = Order an ECHOcardiogram to rule out significant structural heart disease.

STR-ECHO = Order a STRess ECHOcardiogram to rule out structural as well as functional problems that might be leading to their symptoms.

ASYM + RSA/VAGO/BER/IRBBB/PJTW/PRWP = REASS

ASYM + PHT/PROM-T/QW/PRWP = ECHO

ASYM + STD = STR-ECHO

SYM = STR-ECHO

Exercise reversible ST elevation and T-wave changes are physiologic changes. Simple arrhythmias usually disappear with exercise.

Deep inspiration, valsalva, potassium administration, or propranolol may normalize juvenile T waves.

Physiologic hypertrophy has normal systolic and diastolic function.

Exercise-induced sudden cardiac death in athletes is unusual without preexisting heart disease.

The prevalence of HOCM in trained athletes is rare; such changes associated with HOCM select out individuals from sports.

If significant ST depression is seen in ECG, ischemia should be excluded.

It may be difficult to differentiate a healthy athlete with athletic heart from an athletic patient with a diseased heart by resting ECG, if LVH criteria are met echocardiography and exclusion of ischemia is recommended.

Complex ventricular forms of arrhythmia should be evaluated for cardiomyopathy.

Athletes with benign early repolarization with chest pain need to differentiate with pericarditis, myocarditis, ST-elevation infarction.

AV block or Mobitz 2nd/3rd blocks are unusual and are a sign of organic lesion until proved otherwise.

Arrhythmias that become more frequent or symptomatic during exercise ECG warrant more testing.

1. Higgins JP. Normal resting electrocardiographic variants in young athletes. Phys Sportsmed. 2008;36(1):1–7.

HPI: Patient presents with right bundle branch block

PMH: palpitations, dizziness, syncope, history of congenital heart disease

PSH: cardiac surgery

FH: heart block, arrhythmias, pacemakers, sudden cardiac death, infarctions

QRS >100 msec.

Terminal R wave in V1 (rR′, rsR′, qR, R).

Slurred S wave in I, V6.

There should be terminal QRS and T-wave discordance.

RBBB = Right Bundle Branch Block on ECG.

TWD = T-Wave Discordance = the T wave is deflected in the direction opposite the terminal deflection of the QRS complex.

TWC = T-Wave Concordance = the T wave is in the same direction as the terminal deflection of the QRS complex.

CS-STE = Coved or Saddleback ST-segment Elevation: coved ST-segment elevation > = 2 mm (0.2 mV) at J-point with negative T wave in > = 2 right precordial leads (V1–V3) or saddleback ST-segment elevation with a high takeoff ST-segment elevation of > = 2 mm, a trough displaying > = 1 mm ST elevation, and either a positive or biphasic T wave or saddleback or coved ST-segment elevation of < 1 mm—consider.

SYNC = SYNCope.

REASS = REASSure, and no further workup required at this time.

ISCH = Perform ISCHemic burden evaluation (eg, stress test).

BRUG = Consider BRUGada syndrome and refer for further evaluation (eg, electrophysiology evaluation).

PPM = Refer for consideration of Permanent PaceMaker placement.

RBBB + TWD = REASS

RBBB + TWC = ISCH.

RBBB + CS-STE = BRUG

RBBB + SYNC = PPM

A right bundle branch block does not cause harm in otherwise healthy people. The prevalence increases with age, and there is no association for ischemia, infarction, or death.

Pathologic etiologies include hypertension, cardiomyopathy, congenital heart disease, myocarditis fibrosis of the conduction system (Lenegre disease), and interventions.

1. Rotman M, Triebwasser JH. A clinical and follow-up study of right and left bundle branch block. Circulation. 1975;51:477