Sudden death during ambulatory monitoring. Analysis of six cases

Sudden death in patients with congestive heart failure: future directions

Sudden, unexpected cardiac death continues to be a major clinical problem in patients with congestive heat failure. This review summarizes the current state of knowledge regarding the identification and management of these patients. The roles of ambulatory ECG monitoring, electrophysiological testing, signal-averaged ECG, and other methods of predicting increased risk of sudden death are discussed. The modes of sudden cardiac death and the potential mechanisms of ventricular arrhythmias in congestive heart failure are reviewed. Current therapeutic options including antiarrhythmic drugs, neurohormonal blockade, and automatic implantable cardioverter defibrillators are discussed. Finally, future directions and ongoing clinical investigations of the management of these complex patients are considered.

Sudden bradyarrhythmic death in patients with the implantable cardioverter-defibrillator: report of two cases

Two cases of sudden bradyarrhythmic death necessitating cardiopulmonary resuscitation in patients with the automatic implantable cardioverter-defibrillator are described. One patient had sudden bradyarrhythmic death while being monitored in the hospital. This patient could not be resuscitated and represents the first reported sudden cardiac death secondary to bradyarrhythmia in a patient with the automatic implantable cardioverter-defibrillator. The second patient had an out-of-hospital sudden death followed by probable cardioverter-defibrillator discharge, leading to complete heart block with escape ventricular rhythm necessitating immediate temporary pacemaker insertion. These cases highlight the need for bradycardia back-up pacing and event monitoring in the newer tachyarrhythmia management devices.

Diverse mechanisms of unexpected cardiac arrest in advanced heart failure

To define the mechanisms of unexpected cardiac arrest in advanced heart failure, we reviewed the causes of cardiac arrest as established from electrocardiographic monitoring and from clinical and autopsy data in patients hospitalized for cardiac transplantation evaluation and management of advanced heart failure (mean left ventricular ejection fraction, 0.18 +/- 0.08) who were stable while on vasodilator and diuretic therapy such that hospital discharge to home was anticipated. Twenty-one cardiac arrests occurred in 20 of 216 (9%) such patients during a 4-year period. Heart failure was due to coronary artery disease with prior myocardial infarction in 13 patients and nonischemic cardiomyopathy in seven patients. The rhythm at the time of arrest was severe bradycardia or electromechanical dissociation (BA/EMD) in 13 (62%) patients. The precipitating cause of the BA/EMD arrest was coronary artery thrombosis or embolism in two patients, pulmonary embolism in one patient, hyperkalemia in two patients, and unexplained hypoglycemia in one patient. In seven of 13 (54%) patients, a precipitating cause of the bradycardia arrest could not be established. Only eight of 21 (38%) arrests were due to ventricular tachycardia or fibrillation (VT/VF), and all occurred in patients with prior myocardial infarction (p = 0.02 vs. BA/EMD arrests). Two VT/VF arrests were due to acute or recent infarction, and one patient had hyperkalemia. The patients who suffered a BA/EMD arrest were similar to those who had a VT/VF arrest in age, ventricular arrhythmia history, ventricular function, and serum potassium levels. Serum sodium levels were lower in patients with BA/EMD arrests (129 +/- 3 vs. 133 +/- 4 meq/l, p = 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Sudden bradyarrhythmic death in dilated cardiomyopathy: a case report

An 18-year-old male presented with biventricular failure and atrial fibrillation. Detailed investigations revealed the diagnosis of dilated cardiomyopathy. He was put on medical treatment which resulted in symptomatic improvement. One year later he presented with 2 episodes of syncope, with no change in the routine electrocardiogram. A 24-hour ambulatory monitoring was done. The patient died suddenly while on the monitor. Analysis of the terminal event revealed a sudden complete heart block followed by asystole, an event described very rarely in the published literature.

Analysis of ambulatory electrocardiograms in 14 patients who experienced sudden cardiac death during monitoring

The Holter monitors of 14 patients (out of 58,000 Holter recordings performed between 1978 and 1984) who experienced cardiac arrest and expired during the recording period were analyzed. Tachyarrhythmic arrest patients frequently had coronary heart disease, congestive heart failure, and prolonged QTc intervals. The highest incidence of intermediately frequent premature ventricular complexes (PVCs) occurred between 15 and 6 hours prior to death. The frequency of ventricular couplets increased toward the time of arrest. The hours with greatest frequency of ventricular tachycardia (VT) were found to be the last 5 hours of life. An increasing incidence of ST-segment changes greater than 2 mm was noted throughout all of the risk periods until the third hour prior to arrest when the incidence diminished. Conversely, the incidence of lower amplitude ST-segment changes (usually elevation) increased over the final 6 hours. The mean time of death was 0228 hours +/- 5:20. In conclusion, we observed two patterns of Holter-monitored changes which usually occurred prior to death and may represent predictors of sudden death: (1) an increasing incidence of intermediately frequent isolated PVCs followed by increased ventricular couplets and runs of VT; (2) return of high amplitude ST-segment changes toward baseline. To our knowledge, the temporal relationship of the degree of ST-segment deviation to sudden death and the time of sudden death have not been reported in large studies of Holter-monitored sudden death patients.

Terminal cardiac electrical activity in adults who die without apparent cardiac disease

Prolonged electrocardiographic (Holter) recording was performed to analyze terminal electrical events in 23 hospitalized adults who died without apparent cardiac disease. Most patients showed a gradual slowing of heart rate with shifting of cardiac pacemaker downward from the sinus node or atria to the atrioventricular junction and ventricles, resulting in cardiac asystole. Dominant bradyarrhythmia was more common than ventricular tachyarrhythmia (83 vs 17%). Agonal ST-segment elevation was not uncommon (26%). These terminal electrical events became manifest from 1 to 450 minutes (mean 62) before cessation of cardiac electrical activity. Forty-eight percent of the patients continued to show deteriorating sinus or atrial activity up to the last moment. The mechanism of bradycardiac asystole in patients with no apparent cardiac disease may be attributed to generalized anoxic and toxic depression of the sinus node and subsidiary pacemakers, together with neurogenic suppression of these structures.