Basic Dysrhythmia Workshop Part II

Vocabulary flashcards generated from Part II of the Basic Dysrhythmia Workshop lecture notes, covering ECG components, cardiac cycle intervals, dysrhythmia classifications, heart blocks, and therapeutic interventions.

Electrocardiogram (ECG)

A recording that shows cardiac electrical activity, with a $12$-lead ECG providing $12$ different cardiac views.

Isoelectric Line

A straight line produced on an ECG showing no electrical activity, from which waves deflect upward or downward.

P Wave

The first wave of the cardiac cycle, representing atrial depolarization.

P–R Interval

The interval measured from the beginning of the P wave to the beginning of the QRS complex, normally lasting $0.12\text{ to }0.20\text{ seconds}$.

p pulmonale

A pointy (tall) P wave on an ECG indicating right atrial hypertrophy (RAH).

p mitrale

A biphasic (M-shaped) P wave associated with mitral valve prolapse (MVP) or hypertension (HTN).

QRS Complex

A waveform combination composed of Q, R, and S waves representing ventricular depolarization.

QRS Interval

The duration measured from the beginning of the QRS complex to the end of the QRS complex, normally less than or equal to $0.10\text{ seconds}$.

T Wave

The ECG wave following the QRS complex that represents ventricular repolarization.

R on T Phenomenon

A situation where a premature ventricular complex falls on the T wave during the relative refractory period, which can initiate ventricular fibrillation.

QT Interval

The duration measured from the beginning of the Q wave to the end of the T wave, with normal ranges from $0.34\text{ to }0.43\text{ seconds}$.

U Wave

A rare ECG deflection appearing after the T wave that indicates hypokalemia.

ST Segment

The segment between the end of the QRS complex and the beginning of the T wave; it depresses with non-transmural ischemia and elevates with transmural ischemia.

Normal Sinus Rhythm Rules

Criteria for normal sinus rhythm: regular rhythm, heart rate of $60\text{ to }100\text{ bpm}$, rounded P waves before each QRS, PR interval of $0.12\text{ to }0.20\text{ seconds}$, and QRS interval $< 0.10\text{ seconds}$.

Sinus Bradycardia

A sinus rhythm characterized by a regular rhythm with a heart rate of less than $60\text{ bpm}$.

Sinus Tachycardia

A sinus rhythm characterized by a regular rhythm with a heart rate of $101\text{ to }180\text{ bpm}$.

Premature Atrial Contractions (PAC)

Early atrial beats characterized by an abnormal P wave shape that interrupt the underlying regular rhythm.

Atrial Flutter

An atrial dysrhythmia with a regular atrial rhythm, an atrial rate of $250\text{ to }350\text{ bpm}$, and distinct F waves presenting a saw-tooth pattern.

Atrial Fibrillation

An irregularly irregular rhythm with no identifiable P waves and an unmeasurable atrial rate ($700\text{ to }1000\text{ bpm}$).

First Degree AV Block

A heart block characterized by a consistently prolonged PR interval exceeding $0.20\text{ seconds}$ ('If the R is far from P, then you have a FIRST DEGREE').

Second Degree AV Block Type 1 (Wenckebach)

An AV block characterized by progressive PR interval lengthening until a QRS complex is dropped ('Longer, longer, longer, drop! Then you have a WENKEBACH').

Second Degree AV Block Type 2 (Mobitz II)

An AV block where PR intervals remain constant, but some P waves fail to conduct to the ventricles without prior warning ('If some Ps don't get through, then you have MOBITZ II').

Third Degree AV Block

Complete heart block where P waves and QRS complexes occur independently with no relationship between them ('If Ps and Qs don't agree, then you have a THIRD DEGREE').

Premature Ventricular Contraction (PVC)

An ectopic beat originating in the ventricles, characterized by an absent P wave and a wide QRS complex greater than $0.10\text{ seconds}$.

Bigeminy

A dysrhythmia pattern where every second beat is a premature beat, such as a PVC.

Trigeminy

A dysrhythmia pattern where every third beat is a premature beat, such as a PVC.

Ventricular Couplets

Two consecutive premature ventricular contractions (PVCs).

Triplet PVCs (Salvo)

Premature ventricular contractions (PVCs) occurring in groups of three.

Ventricular Tachycardia (VT)

A rapid ventricular dysrhythmia with a rate usually between $150\text{ to }250\text{ bpm}$, absent P waves, and QRS duration $> 0.10\text{ seconds}$.

Torsades de Pointes

A form of polymorphic ventricular tachycardia whose waveform outline resembles a party streamer.

Ventricular Fibrillation

A chaotic, extremely irregular lethal rhythm with no measurable heart rate, no P waves, and no QRS complexes.

Asystole

The complete absence of cardiac electrical activity and mechanical contraction, presenting as a flat line on the ECG.

PEA (Pulseless Electrical Activity)

A clinical condition where organized electrical activity is seen on the cardiac monitor, but no palpable pulse is present, caused by reversible 6 H's and 6 T's.

Defibrillation

An unsynchronized electrical shock delivered to the heart to terminate lethal dysrhythmias such as pulseless Ventricular Tachycardia and Ventricular Fibrillation.

Synchronized Cardioversion

An electrical shock timed specifically to coincide with the R wave on the ECG, used for unstable dysrhythmias with a pulse (VT with pulse, A-Fib, A-Flutter, SVT).

Implantable Cardioverter Defibrillator (ICD)

An implanted electronic device that automatically defibrillates when a lethal rhythm is detected and cardioverts when Ventricular Tachycardia is detected.