ECG Rhythm Characteristics and Interpretation

Vocabulary flashcards covering various cardiac rhythms, their ECG characteristics, rates, wave intervals, and definitions based on lecture transcript notes.

Normal Sinus Rhythm (NSR)

Sinus Tachycardia

Sinus Bradycardia

Premature Atrial Contractions (PAC)

An irregular cardiac rhythm with a rate usually $< 100\text{ per minute}$ (dependent on underlying rhythm), featuring early and upright P waves that are different from sinus, PR interval of $0.12 - 0.20\text{ seconds}$ (different from sinus), and qRs of $0.04 - 0.10\text{ second}$.

Atrial Flutter

An atrial rhythm with an atrial rate of $250 - 350$ and ventricular rate commonly $150$. Atrial rhythm is regular, ventricular is regular or irregular; P waves are not identifiable, featuring uniform F waves (sawtooth or picket fence), non-measurable PRI, and qRs of $0.04 - 0.10\text{ second}$.

Atrial Fibrillation

An irregular rhythm with an atrial rate of $400 - 700$ and ventricular rate of $160 - 180\text{ per minute}$. Characterized by no identifiable P waves (f waves may be seen), unmeasurable PRI, and usually normal qRs.

Premature Junctional Contraction (PJC)

An irregular rhythm with rate usually $< 100\text{ per minute}$ (dependent on underlying rhythm), featuring P waves that are inverted before or after qRs or not visible, PR interval $< 0.12\text{ second}$ when inverted P is before qRs, and qRs of $0.04 - 0.10\text{ second}$.

Junctional Rhythm

A regular rhythm with an accelerated rate of $61 - 100$, featuring P waves inverted before or after qRs or not visible, PR interval $< 0.12\text{ second}$ when inverted P is before qRs, and qRs of $0.04 - 0.10\text{ second}$.

Junctional Tachycardia

A cardiac rhythm sharing the same causes as Paroxysmal Atrial Tachycardia (PAT) and ECG characteristics of Junctional Rhythms, with a rate of $101 - 200$.

Accelerated Junctional

A cardiac rhythm sharing the same causes as Paroxysmal Atrial Tachycardia (PAT) and ECG characteristics of Junctional Rhythms, with a rate of $60 - 100$.

Supraventricular Tachycardia (SVT)

A term used when unable to distinguish which rhythm is present, characterized by an absolutely regular rhythm, rate $> 150\text{ per minute}$, non-visible P waves (PRI not measurable), and normal qRs of $0.04 - 0.10\text{ sec}$.

Premature Ventricular Complex (PVC)

An ectopic impulse with rate dependent upon underlying rhythm, R-R rhythm, usually absent P waves (if present, not associated with PVC), qRs of $0.12\text{ second}$ or greater (bizarre and notched), and ST & T often opposite in direction to qRs.

Isolated PVC

A PVC timing classification corresponding to one Premature Ventricular Complex in a row on an ECG strip.

Pair / Couplet (PVC)

A PVC timing classification corresponding to two Premature Ventricular Complexes in a row.

Bigeminy

A PVC pattern where a Premature Ventricular Complex occurs every other beat.

Trigeminy

A PVC pattern where a Premature Ventricular Complex occurs every third beat.

Uniformed PVC

Premature Ventricular Complexes that exhibit a similar shape or morphology.

Multiformed PVC

Premature Ventricular Complexes that exhibit different shapes or morphologies.

R-on-T Phenomenon

A PVC location timing where a Premature Ventricular Complex falls directly on the T wave of the complex preceding it.

Ventricular Tachycardia

A rhythm consisting of a group of three or more PVCs in a row at a rate $> 100\text{ per minute}$ (usually not $> 220$); rhythm is usually regular with wide ($0.12\text{ sec}$) bizarre qRs and ST/T wave in the opposite direction of qRs.

Ventricular Fibrillation

A cardiac rhythm with no rate, no regularity (chaotic undulating waves), no P waves, no qRs, no ST/T wave, no organized activity, and no cardiac output or pulse.

Idioventricular Rhythm

A rhythm with a rate of $20 - 40\text{ per minute}$, regular R-R, no P waves associated to qRs, qRs $> 0.12\text{ sec}$ (notched, bizarre appearance), and ST/T in the opposite direction of qRs.

Accelerated Idioventricular Rhythm

An Idioventricular Rhythm with a rate greater than $40$ to $100\text{ per minute}$.

Asystole

A state with a ventricular rate of $0$ and no qRs complexes; rhythm is absent unless P waves are present (which may be regular or irregular).

1st degree AV Block

An AV block characterized by a 1P:1qRs ratio and a prolonged PR interval ($> 0.20\text{ sec}$ but not $> 0.40\text{ sec}$).

2nd degree AV Block, Type I Mobitz I Wenckebach

An AV block with more P waves than qRs, unequal R-R intervals, and a PR interval that progressively increases in a cycle until a P wave appears without a qRs complex.

2nd degree AV Block, Type II Mobitz II

An AV block with more P waves than qRs, consistent PR interval, normal or wide qRs (bundle branch block), and R-R intervals that are either equal or not equal.

3rd degree AV Block

An AV block with more P waves than qRs where P waves are not related to qRs (P too close, P too far), PRI varies greatly, qRs is normal or wide, and R-R intervals are equal.

Pulseless Electrical Activity (PEA)

A condition caused by H's and T's, severe cardiac damage, or respiratory failure, where the ECG rhythm may look normal but will NOT have a pulse.