EKG Lecture Scott Ewing April 5, 2005

Question:What is the rhythm in this 66-year-old woman Question:What is the rhythm in this 66-year-old woman?  * *  Difficulty rating Answer:Atrial fibrillation with a rapid ventricular response (about 150/min). Non-specific ST-T changes are also noted.

Question:What arrhythmias are present in this EKG from a middle-aged male?  * *  Difficulty rating Answer:Atrial fibrillation (moderate ventricular response) and frequent premature ventricular complexes (PVCs). The PVCs are multifocal with two distinct morphologies. The EKG does not show other specific abnormalities (the isolated Q wave in lead III is non-diagnostic).

Question:What arrhythmia is present in this wide-QRS-complex tachycardia?  * * *  Difficulty rating a)   Monomorphic ventricular tachycardiab)   Polymorphic ventricular tachycardiac)   Atrial fibrillation with left bundle branch blockd)   Atrial flutter with left bundle branch blocke)   Atrial fibrillation with Wolff-Parkinson-White pre-excitation Answer:c) Atrial fibrillation with left bundle branch block. Note: The coarse atrial fibrillatory waves (lead V1) may be mistaken for atrial flutter waves. However, with fibrillation (verus flutter) the atrial activity varies continuously and usually the ventricular response is completely variable. The QRS complex here shows a typical left bundle branch block morphology with secondary ST-T abnormalities.

Question:What is the arrhythmia in this 73-year-old with very severe coronary disease, status-post inferior and anterior-lateral Q-wave myocardial infarction?  * *  Difficulty rating a)   Atrial fibrillationb)   Atrial flutter with variable blockc)   Multifocal atrial tachycardiad)   Sinus tachycardia with atrial premature beatse)   Atrial tachycardia with type I (AV Wenckebach) block Answer:a) Atrial fibrillation The highly irregular ventricular response and the variable, oscillatory atrial activity (see V1, e.g.) are classic for atrial fibrillation.

Question:What arrhythmia is present in this elderly woman with a history of mitral valve replacement for rheumatic mitral valve disease?  *  Difficulty rating a)   Atrial flutterb)   Atrial fibrillationc)   Junctional rhythmd)   Sinus rhythm with frequent premature atrial complexese)   Multifocal atrial tachycardia Answer:b) The patient had long standing atrial fibrillation. There are no discrete P waves which excludes sinus rhythm or multifocal atrial tachycardia see (Case # 149). The erratic irregular oscullatory baseline with an erratic ventricular response is typical of atrial fibrillation. No flutter waves are seen (see Case # 52). The scooping of the ST-T waves in the inferolateral leads are consistent with digitalis effect

Question:The following EKG shows which of the following Question:The following EKG shows which of the following?  * * *  Difficulty rating a)   Atrial flutter with 2:1 blockb)   Atrial flutter with 3:1 blockc)   Atrial flutter with variable blockd)   Atrial fibrillatione)   Parkinsonian tremor artifact Answer:c) The EKG shows typical atrial flutter waves. The ventricular response is not highly irregular as in atrial fibrillation, but is also not strictly regular. The rate here has a definite pattern; the conduction is not constantly 3:1 or 4:1, but rather a combination of these intervals. Parkinsonian tremor may simulate atrial flutter or fibrillation. In such cases the underlying rhythm is usually recognizable upon close inspection.

Question:55-year-old woman with rheumatic mitral valve disease and a narrow complex tachycardia. The rhythm is:  * * *  Difficulty rating a)   Sinus tachycardiab)   Atrial fibrillationc)   Atrial flutter with 2:1 AV conductiond)   AV nodal reentrant tachycardiae)   Ectopic atrial tachycardia Answer:c) Typical atrial flutter waves are present (negative in lead II; biphasic in V1) at a rate of about 270/min with 2:1 conduction. Note the non-conducted atrial flutter waves subtly present in the ST segment in V1. Atrial flutter may mimic all of the arrhythmias given in the other choices. Relatively low voltage QRS complexes are also present in this patient who had pleural effusions.

Question:What is the rhythm in this 79-year-old woman with complaint of shortness of breath?  * * *  Difficulty rating a)   Multifocal atrial tachycardiab)   Ventricular tachycardiac)   Atrial flutter/fibrillation with rapid ventricular responsed)   Sinus tachycardiae)   Paroxysmal supraventricular tachycardia with AV nodal reentry Answer:The rhythm is atrial flutter/fibrillation with a rapid ventricular response rate of about 120 bpm with left axis deviation (LAD) and a borderline intraventricular conduction delay (QRS duration=0.11 second). Slow R progression and non-specific ST-T changes are present. There is no evidence of discrete P waves, either normal or ectopic, excluding sinus tachycardia or a type of atrial tachycardia. The baseline shows some artifact with atrial flutter/coarse atrial fibrillatory activity. The regularized response at the beginning is consistent with flutter and the more erratic response response later suggests intermittent atrial fibrillation. Not uncommonly, these two "cousin" atrial tachyarrhythmias alternate or co-exist, so the term flutter/fibrillation, or "fib-flutter" is used clinically.

Question:80 year-old man presented to emergency department complaining of fatigue and shortness of breath? What is the rhythm?  * *  Difficulty rating a)   Sinus tachycardiab)   Atrial tachycardiac)   AV nodal reentrant tachycardia (AVNRT)d)   Atrial flutter with 2:1 conductione)   Atrial fibrillation Answer:This EKG shows typical atrial flutter with 2:1 block. The atrial rate is 320 with 2:1 AV block (conduction), yielding a ventricular response is 160 bpm. There are classic flutter “F” waves (consistent with a typical counterclockwise right atrial reentrant circuit) giving a “saw tooth” appearance to the atrial activity. (see also Cases 87,129,202.) A resting rate of 160 bpm excludes sinus tachycardia in this age group. Atrial fibrillation is ruled out because of the regularity of the ventricular response. Apparent flutter waves at 320/min exclude AVNRT or atrial tachycardia. This patient was treated with calcium channel blockade for rate control and electrically cardioverted to sinus rhythm.

Question:59-year-old female with sudden palpitations and lightheadedness.  * * * *  Difficulty rating Answer:Atrial fibrillation with the Wolff-Parkinson-White (WPW) syndrome, with conduction down the bypass tract. This is for the most part a wide complex tachycardia with a rate of about 230 beats/min. The differential diagnosis includes 1) ventricular tachycardia, 2) supraventricular tachycardia with aberrancy, and 3) WPW with conduction down the bypass tract. The major clues include the "irregularly irregular" rhythm and the extremely rapid rate. Ventricular tachycardia may be mildy irregular but this degree of irregularity would be unusual at this very fast rate. The short refractory period of certain bypass tracts can allow extremely rapid heart rates, especially during atrial fibrillation. A correct diagnosis is very important because drugs that slow AV conduction (verapamil, beta blockers, digoxin, adenosine) are contraindicated. These drugs can facilitate preferential conduction down the bypass tract and the atrial fibrillation can degenerate to ventricular fibrillation. Call EP fellows stat! A drug of choice is IV procainamide and if this is unsuccessful, DC cardioversion should be performed promptly.

Question:Tachycardia and a touch of cyanosis (rhythm and blues) Question:Tachycardia and a touch of cyanosis (rhythm and blues). What is major finding in this patient with congestive heart failure (CHF)?  * * *  Difficulty rating Answer:The major finding is narrow complex tachycardia with atrial rate of about 300 indicating atrial flutter and slightly variable ventricular response (2:1 conduction, some 3:1 and probably some Wenckebach). Atrial flutter is sometimes mistaken (by housestaff at other institutions) for sinus tachycardia. Look, for instance, at V1 where the flutter waves are hard to see vs. lead II where they are more apparent. If only a V1 type lead were available, the mechanism could be readliy mistaken.

Question:Rapid palpitations. Why?  * *  Difficulty rating Answer:Atrial flutter with 2:1 conduction. Don't overlook subtle "extra" atrial wave (it's NOT a true P wave, but a flutter wave) in the early ST segment. Atrial flutter with 2:1 conduction (block) is often mistaken for sinus tachycardia or paroxysmal supraventricular tachycardia (PSVT), as discussed elsewhere in this problem set.