| A | atrium |
| AEI | atrial escape interval |
| AH | atrial-His |
| AN | atrionodal |
| AP | accessory pathway |
| APC | atrial premature complex |
| APD | atrial premature depolarization |
| ARP | absolute refractory period/atrial refractory period (pacing) |
| ARVC | arrhythmogenic right ventricular cardiomyopathy |
| AT | atrial tachycardia |
| ATI | atrial tracking interval |
| ATP | adenosine triphosphate |
| AV | atrioventricular |
| AVI | AV interval |
| AVN | AV node |
| AVRT | atrioventricular reentrant tachycardia |
| AVNRT | AV nodal reentrant tachycardia |
| bpm | beats per minute |
| COPD | chronic obstructive pulmonary disease |
| CT | crista terminalis |
| CTI | cavo-tricuspid isthmus |
| ECG/EKG | electrocardiogram |
| ECS | extracellular space |
| EPS | electrophysiologic study |
| ER | early repolarization |
| ERP | effective refractory period |
| H | His |
| HBE | His bundle electrogram |
| HPS | His-Purkinje system |
| HR | heart rate |
| HV | His-ventricular |
| IART | intra-atrial reentry tachycardia |
| ICD | implanted cardiac defibrillator |
| IST | inappropriate sinus tachycardia |
| JPC | junctional premature complex |
| JT | junctional tachycardia |
| LA | left arm |
| LAD | left anterior descending |
| LAFB | left anterior fascicular block |
| LAO | left anterior oblique |
| LB | left bundle branch |
| LBBB | left bundle branch block |
| LCx | left circumflex |
| LGL | Lown-Ganong-Levine |
| LL | left leg |
| LM | left main |
| LPFB | left posterior fascicular block |
| LQTS | long QT syndrome |
| LRI | lower rate interval |
| LRL | lower rate limit |
| LVE | left ventricular enlargement |
| LVH | left ventricular hypertrophy |
| LVOT | left ventricular outflow tract |
| MAT | multifocal atrial tachycardia |
| MDP | maximum diastolic potential |
| MI | myocardial infarction |
| MTI | maximum tracking interval |
| MTR | maximum tracking rate |
| mV | millivolts |
| N | nodal |
| NH | nodal-His |
| PAT | paroxysmal atrial tachycardia |
| PAVBP | post-atrial ventricular blanking period |
| PDA | posterior descending artery |
| PE | pulmonary embolus |
| PEA | pulseless electrical activity |
| PMT | pacemaker-mediated tachycardia |
| POTS | postural orthostatic tachycardia syndrome |
| PRWP | Poor R wave progression |
| PVARP | post-ventricular atrial refractory period |
| PVC | premature ventricular complex |
| QT | QT interval |
| QTc | Corrected QT interval |
| RA | right arm |
| RB | right bundle branch |
| RBBB | right bundle branch block |
| RCA | right coronary artery |
| RP | resting potential |
| RRP | relative refractory period |
| RVE | right ventricular enlargement |
| RVH | right ventricular hypertrophy |
| RVOT | right ventricular outflow tract |
| SA | sinoatrial |
| SN | supernormal period |
| SNRT | sinus node recovery time |
| SQTS | short QT syndrome |
| SSRI | selective serotonin uptake inhibitor |
| STEMI | ST elevation myocardial infarction |
| SVT | supraventricular tachycardia |
| TARP | total atrial refractory period |
| TdP | torsades de pointes |
| TP | threshold potential |
| URL | upper rate limit |
| VAI | ventricular-atrial interval |
| VEI | ventricular escape interval |
| VPB | ventricular premature beat |
| VPC | ventricular premature complex |
| VPD | ventricular premature depolarization |
| VRP | ventricular refractory period |
| VSP | ventricular safety pacing |
| VT | ventricular tachycardia |
| WCT | wide complex tachycardia |
| WPW | Wolff-Parkinson-White |