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

Abstract

Summary: The Holter monitors of 14 patients (out of58, 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 f 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 fresuent 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.

Silent Myocardial Ischaemia: A Review of the Literature for Prehospital Care Providers

“…Savage et al were able to demonstrate marked ST segment depression or elevation indicative of myocardial ischaemia in 9 of 14 patients who experienced sudden cardiac death whilst wearing an ambulatory ECG monitor. 56 Similar conclusions have also been made by several other authors. 57,58 The frequency of silent myocardial infarction also poses several diagnostic challenges.…”

ECG Changes, Emotional Arousal, and Subjective State

“…This prolongation of QTc during ischaemic episodes was coupled with a longer duration of the ST segment. It has been suggested by several authors that prolongation of QTc is associated with ventricular arrhythmias and sudden death (Ahnve, Lundman, & Shoaleh-var, 1978; Savage et al, 1987; Schwartz & Wolf, 1978; Taylor et al, 1981) and higher rate of reinfarction (Ahnve, Helmers, Lundman, Rehnqvist, & Sjögren, 1980; Hust et al, 1984). In a study with 304 patients who underwent coronary angiography because of suspected CHD (Krämer et al, 1984), QTc increased from patients with one vessel disease to patients with three vessel disease, especially in patients with impaired left ventricular function.…”

Mechanism of spontaneous initiation of ventricular fibrillation in patients with implantable defibrillators

“…Repolarization heterogeneity in the cardiac tissue appears to play a major role as a mechanism of spontaneous initiation of VF by facilitating unidirectional block and subsequent re‐entry. Due to the lack of noninvasive methods for quantifying repolarization heterogeneity in human heart in vivo, repolarization heterogeneity has been indirectly evaluated by characterizing the coupling interval (CI) of premature ventricular complexes (PVCs) that initiate VF from sinus rhythm 1,2 . In addition, the patterns of activation time intervals immediately preceding VF initiation have been classified into early‐ and late‐coupled PVC, 3,4 long‐short (LS), 5 short‐long (SL), and short‐long‐short (SLS) sequences 6,7 .…”