Janet Lipski

Value of holter monitoring in assessing cardiac arrhythmias in symptomatic patients

Holter electrocardiographic monitoring in 55 symptomatic patients with syncope, palpitations or dizziness uncovered significant arrhythmias in 30 patients (55 percent). By providing an observation period of at least 24 hours including a period of sleep, the procedure aided detection and diagnosis in both symptomatic and asymptomatic patients of transient arrhythmias or conduction abnormalities not documented by routine electrocardiograms. Bradyarrhythmias accounted for the majority of arrhythmias recorded in 21 or 30 symptomatic patients (70 percent); 15 had sinus bradycardia (35 to 55 beats/min) alone and 6 also had long episodes of sinus arrest of up to 5 seconds. Two had sinus bradycardia with periods of atrioventricular block with Wenckebach phenomenon. Five patients had a tachycardia-bradycardia syndrome; three had other episodic arrhythmias and one had pacemaker failure. In 15 (60 percent) of the 25 patients without arrhythmias, monitoring did not document the cause of symptoms. Holter monitoring is of considerable value in assessing the efficacy and adequacy of drug treatment, especially in patients with known heart disease, and in detecting pacemaker malfunction. However, very long periods of monitoring may be needed to make a diagnosis in those with only sporadic symptoms.

The effect of heroin and multiple drug abuse on the electrocardiogram

Abstract The electrocardiograms (ECG) of 75 asymptomatic individuals admitted to a methadone treatment program were analyzed to determine the effect of street heroin and other drugs of abuse. All patients were free of cardiac, renal, or pulmonary disease and had no laboratory abnormalities. Two groups of patients were studied. In Group I there were 34 patients on heroin only which was taken within 24 hours of the ECG. Abnormalities were noted in 55 per cent; QT c prolongation was found in 19 per cent, and significant bradyarrhythmias were found in 19 per cent. In Group II there were 41 patients on methadone with multiple drug abuse; changes were found in 66 per cent. QT c prolongation was noted in 34 per cent, prominent U waves in 32 per cent, and bradyarrhythmias were found in 32 per cent. It is now a well-known fact that the sudden death syndrome in addicts may not be a pharmacologic or dosage-related phenomenon. The existence of conduction, depolarization, and repolarization abnormalities, as well as bradyarrhythmias in a significant number of drug-dependent individuals may play a role in the production and facilitation of lethal arrhythmias and may be the mechanism of the acute fatal reaction.

New Q waves after coronary artery bypass surgery for angina pectoris

Abstract Pre- and postoperative electrocardiograms were evaluated in 44 patients with angina pectoris who underwent single or multiple coronary artery bypass procedures. Two groups were identified: Group A, 37 patients with bypass procedures only, and Group B, 7 patients with bypass procedures and additional surgery (valve replacement in 4 and ventricular resection in 3). Preoperative electrocardiograms showed abnormal Q waves in 14 of 37 patients in Group A and in 3 of 7 patients in Group B. After coronary artery bypass, new Q waves appeared in 11 of 37 patients (30 percent) in Group A, including 1 of 9 (11 percent) with one-vessel disease on preoperative coronary arteriograms, 7 of 20 (35 percent) with, two-vessel disease and 3 of 8 (37.5 percent) with three-vessel disease; new intraventricular conduction abnormalities appeared in 4 of the 37. None of the seven patients in Group B had new Q waves postoperatively, but three had intraventricular conduction abnormalities. There was no correlation between new Q waves and preoperative values for left ventricular end-diastolic pressure. In Group A, new Q waves were demonstrated in 2 of 9 patients (22 percent) with one coronary bypass procedure, 5 of 21 patients (24 percent) with two bypass procedures and 4 of 6 patients (67 percent) with three bypass procedures. The single patient who had four coronary artery bypass procedures had no new Q waves after operation. It is evident that the prevalence of new Q waves was greater in patients who had two- or three-vessel disease by coronary arteriography as well as in those who had three coronary artery bypasses. Postoperative clinical course and mortality were not affected.

Effectiveness of pacemaker treatment in the bradycardia-tachycardia syndrome

Thirty-one patients with the bradycardia-tachycardia syndrome treated with permanent ventricular pacemakers were studied. All were symptomatic before pacemaker insertion, and their symptoms were not controlled with drug therapy alone. Bradycardia and tachycardia associated with multiple arrhythmias were present in all cases; heart rate was less than 40 beats/min in 58 percent of patients and more than 140 beats/min in 71 percent. Conduction abnormalities were present in 61 percent. After insertion of a demand pacemaker, 27 patients (87 percent) were symptom-free for 1 month to 5 years. Although four patients with a normally functioning pacemaker continued to have recurrent arrhythmia, the presence of a pacemaker facilitated further pharmacologic treatment of the disturbance. Pacemaker insertion has been found to be a satisfactory method of treating the symptoms and preventing the recurrence of arrhythmias in patients with the bradycardia-tachycardia syndrome by allowing the use of digitalis and other antiarrhythmic agents.

Prinzmetal's variant angina: A clinical and electrocardiographic study

Abstract Eight patients with “variant” angina pectoris were analyzed for electrocardiographic features before, during, and after chest pain. All patients showed marked concave ST-segment elevations with upright T waves during pain which disappeared with subsidence of pain. Ventricular dysrhythmias were noted in four patients. Three had ventricular tachycardia and one had an idioventricular rhythm. In addition, one patient had a transient Mobitz II atrioventricular block. The electrocardiogram during pain at the time of right ventricular pacing in one patient revealed elevated ST-segments with upright T waves in the previously involved leads. Coronary arteriography in four patients revealed an isolated single lesion in three and normal coronary vessels in the other. The possible basis of the electrocardiographic findings is discussed.

The effect of bretylium tosylate on the normal and digitalis-sensitized dog heart

Abstract Investigations were made of the effect of bretylium tosylate, an antiarrhythmic drug, on automaticity, atrioventricular conduction time, intraventricular conduction time, and sinus rate in the digitalis-sensitized and normal, intact dog heart. Bretylium and acetylstrophanthidin decreased sinus rate 27 and 18 per cent, respectively. Acetylstrophanthidin given after bretylium pretreatment caused a 36 per cent decrease in sinus rate. Bretylium and acetylstrophanthidin each increased atrioventricular conduction time (P-H interval). With right atrial pacing at a constant rate, bretylium increased atrioventricular conduction time 36 per cent while acetylstrophanthidin increased this time by 25 per cent. Together, bretylium and acetylstrophanthidin increased conduction time 111 per cent, chiefly in the A-V-H subinterval. Bretylium initially increased then subsequently decreased automaticity. The average ventricular escape time increased 190 per cent by bretylium. Acetylstrophanthidin, given after bretylium, decreased ventricular escape time 50 per cent, as compared to 80 per cent when given alone. Bretylium produced ventricular premature systoles and ventricular tachycardia in 7 of 17 dogs during the short period of increased automaticity. This finding as well as the effect to decrease sinus rate and to increase atrioventricular conduction time may limit the clinical usefulness of bretylium.