The impact of transtelephonic documentation of arrhythmia on morbidity and mortality rate in sudden death survivors.

A post hospital follow-up system based on predetermined antiarrhythmic strategies and telephone transmitters used to record ECGs was helpful in managing post hospital course and improved survival in patients with a history of out-of-hospital sudden death. All patients underwent therapy guided by serial electrophysiologic testing. Of the 47 patients, 19 used the telephone transmitter system and 28 did not. During follow-up, residual symptomatic and silent ventricular arrhythmia was documented in 78% of patients using telephone transmitters. Ventricular tachycardia was transmitted in six patients--all survived. During an average 15-month follow-up, 1 of 19 patients using the telephone transmitter system died vs 12 deaths among the 28 patients who did not use the system (p less than 0.005). These results were independent of ejection fraction, presence of congestive heart failure, amiodarone therapy, and the outcome on electrophysiologic therapy. Thus, patients with a history of out-of-hospital sudden death, discharged following electrophysiologic guided therapy, require repeated antiarrhythmic dose titration for side effects or residual ventricular arrhythmia. Prompt diagnosis and treatment of potentially fatal arrhythmia is crucial and feasible, especially with regular ECG checks through telephone transmission.

Serum, red blood cell and whole blood magnesium in patients with uncomplicated acute myocardial infarction.

Serum, whole blood and red blood (intracellular) magnesium determinations were made in 52 patients, without other factors predisposing to hypomagnesemia, admitted to a coronary care unit. Acute uncomplicated myocardial infarction was documented in 31 and the serum cardiac enzymes as well as the electrocardiogram remained nondiagnostic in 21 patients. There was no significant difference in the serum magnesium level in the two groups. An increasing trend with time was noted in the serum (p less than 0.001) and whole blood magnesium (p less than 0.005) during the first 4 days postmyocardial infarction. The whole blood magnesium as well as the red blood (intracellular) magnesium was higher (p less than 0.01) in myocardial infarction patients. There was no significant difference in the hematocrit or other electrolytes during this time.

Clinical hypomagnesemia, coronary spasm and cardiac arrhythmia.

The case report demonstrates another case of hypomagnesemia with electrocardiographic evidence of acute myocardial ischemia due to coronary spasm. The patient was successfully treated with intravenous, followed by oral, magnesium sulfate. Magnesium therapy may be justified especially in patients with prolonged QT intervals, cardiac arrhythmias and hypokalemia with hypomagnesemia.

Relationship of psychologic factors to frequent symptomatic ventricular arrhythmia.

Since there is very little available systematic information on the psychological profile of patients with cardiac arrhythmia, a battery of 12 standardized personality inventories was administered to 102 patients ranging in age from 19 to 69 years. Thirty-eight patients with frequent ventricular premature beats (more than 30 per hour) without myocardial infarction were significantly more psychologically symptomatic than 34 age- and sex-matched general medical/surgical patients. The variables found to be significant portray the patient with frequent ventricular premature beats without myocardial infarction: high scores for hysteria, less moral orientation, more anxiety, depression and social alienation, and an inhibited and low respectful style. This combination of psychological variables produced a discriminant function (p less than 0.001) that accounted for 53 percent of the variance between the arrhythmia/no myocardial infarction group and the medical/surgical control group and could correctly predict group membership in 83.3 percent of cases. These results may have further implications in nonpharmacologic and psychotropic adjuncts to antiarrhythmic therapy.

Observations on serum and red blood cell magnesium changes in treadmill exercise-induced cardiac ischemia.

To evaluate changes in magnesium levels with treadmill exercise-induced coronary insufficiency, 59 consecutive patients were studied. In addition to electrocardiographic monitoring, hematocrit, total protein, whole blood, serum and red blood cell magnesium determinations were made before and after exercise testing. Fifteen patients had positive exercise test, 18 did not complete, and 26 had negative exercise test. There was no significant difference in the serum and red blood cell magnesium on the basis of stress test results for ischemia. Although whole blood magnesium, hematocrit, and total proteins increased (P less than .05) in both groups, we did not find a significant change in magnesium homeostasis.

Effects of nadolol on the spontaneous and exercise-provoked heart rate of patients with chronic atrial fibrillation receiving stable dosages of digoxin.

Nadolol, a long-acting beta-adrenergic-blocking agent, was evaluated in 20 patients with chronic atrial fibrillation by means of a randomized, double-blind, crossover study. Patients were required either to demonstrate resting heart rates in excess of 80 bpm or to show a rate of 120 bpm or an increment of greater than 50 bpm during mild treadmill exercise provocation (3 minutes, 1.75 mph, 10% grade). With placebo the group averaged a heart rate of 92 +/- 19 bpm, determined by 24 hours of ambulatory ECG recordings; this rate was significantly reduced to 73 +/- 16 bpm (p less than 0.001) with nadolol (mean dosage, 87 +/- 43 mg/day). During standardized exercise testing, heart rates increased to 153 +/- 26 bpm with placebo and to 111 +/- 24 bpm with nadolol (p less than 0.001), representing 65% and 52% increments, respectively. Digoxin blood levels averaged 0.8 +/- 0.5 ng/ml with placebo and were similar with nadolol (0.9 +/- 0.4; p = NS). Total exercise time on a modified Bruce treadmill protocol was 466 +/- 143 seconds with placebo and was significantly decreased by nadolol (380 +/- 143; p less than 0.01). During initial dose titration with nadolol, one patient was dropped from study for intolerable fatigue and one for worsened claudication. No patients were dropped from the double-blind treatment periods, although two patients receiving nadolol and one patient receiving placebo complained of moderate fatigue. We conclude that nadolol is a safe and effective agent for the control of spontaneous and exercise-provoked heart rates in patients with chronic atrial fibrillation who were already receiving digoxin treatment.

Severe thrombocytopenia as a result of contrast left ventricular angiography.

A case report of a 29-year-old Hispanic male who developed an acute thrombocytopenic reaction immediately following a cardiac catheterization using Hypaque-M radiographic dye. Laboratory studies immediately post-catheterization revealed a platelet count of 11,000 with a subsequent further drop to a low of 4,000. A need for the prompt identification and possible causes of this unusual reaction are discussed. Recovery occurred following treatment with corticosteroids.

Characteristics of ventricular ectopic beats in patients with ventricular tachycardia. A 24-hour Holter monitor study.

A total of 99 consecutive 24-hour Holter recordings with ventricular tachycardia were reviewed. Ventricular premature beats which occurred alone, and ventricular premature beats which initiated ventricular tachycardia were examined to determine which characteristics correlated with occurrence of ventricular tachycardia and which predicted rate and duration of ventricular tachycardia. The preceding R-R interval, the coupling interval, and a ratio of the two were examined. We found that ventricular tachycardia rate and duration increase with a shorter coupling interval, and the coupling interval/preceding R-R ratio was significantly different in single beats not initiating ventricular tachycardia. The ratio for the beat initiating ventricular tachycardia was smaller, indicating more prematurity.

Right bundle branch block with periods of alternating left anterior and left posterior hemiblock. Clinical evidence of incomplete fascicular block.

The case presented had an electrocardiographic pattern of complete right bundle branch block with alternating periods of left anterior hemiblock and left posterior hemiblock. During one of the periods of alternating hemiblock, an His bundle electrogram was recorded and the His Purkinje (H-V interval) conduction time was within normal limits. In a second episode of alternating hemoblock, periods of Mobitz type II second-degree A-V block were noted. It is postulated that this case provides clinical evidence that incomplete block of a fascicle may occur in spite of an electrocardiographic pattern of complete fascicular block. It is thought that the periods of alternating hemiblock result from a changing relationship between conduction velocity and refractory period.

A-V block in accidental hypothermia.

His bundle electrocardiography was performed on a patient with accidental hypothermia on whom the standard electrocardiogram (ECG) showed absent P waves, prominent J waves and a slightly irregular rhythm. Sino-ventricular conduction and a prolonged AH interval not responsive to atropine were found. These abnormalities reversed with rewarming.

Nonprolapsing atrial myxoma; clinical, echocardiographic, and angiographic correlations.

The auscultatory features typical of myxoma were absent in a patient with nonprolapsing left atrial myxoma. Angiocardiographic and echocardiographic findings including B-mode cross-sectional scanning are presented.