Ventricular tachycardia: historical perspective.

Ventricular tachycardia is now diagnosed frequently in patients with organic heart disease. Although ventricular tachycardia was first demonstrated electrocardiographically 75 years ago, the natural history, fundamental mechanisms, and optimal management have remained elusive. Early observers commented on the rarity of occurrence and poor prognosis associated with this arrhythmia, yet with time, some patients with ventricular tachycardia were reported to survive for prolonged periods. Because of the sporadic nature of the arrhythmia and its variable prognosis, assessment of the efficacy of therapies has been difficult. A wide variety of treatments has been advocated with enthusiasm, but only a few have been consistently reported to be effective. Citation of historical data to claim benefit from new treatments should be viewed with caution.

Predictors of survival after tricuspid valve surgery.

The long-term survival rate of 74 consecutive patients who underwent multiple cardiac valve surgery including tricuspid valve surgery was analyzed to identify predictive preoperative clinical variables. Univariate analysis revealed that male sex (P less than 0.04), symptoms of New York Heart Association functional class IV heart failure (p less than 0.004), ascites or pulmonary edema (p less than 0.01), high preoperative bilirubin level (p less than 0.012), mean pulmonary artery pressure greater than 40 mm Hg (p less than 0.038) and pulmonary vascular resistance greater than 6 Wood units (p less than 0.02) were each associated with an increased risk of death after surgery. Stepwise multivariate analysis indicated that severity of preoperative edema and mean pulmonary artery pressure were the most predictive combination of independent variables. These 2 variables were used to calculate an estimated probability of 1-year survival after surgery for patients with multivalvular cardiac decompensation. Recognition of these preoperative variables should assist the clinician in determining the risk of surgical intervention.

Atrial flutter with exit block.

The mechanism of atrial flutter is controversial. A 76-year-old woman with rheumatic heart disease was referred to our clinic with an unusual rhythm disturbance which initially appeared to be classic atrial flutter at a rate of 300 beats/min. Later tracings, however, demonstrated a rate exactly one-half that of the earlier ECGs, with an identical p-wave morphology and vector. This latter rhythm also behaved in a manner expected for a flutter mechanism in that both spontaneously and with carotid pressure high-degree atrioventricular block occurred without alteration of the underlying atrial mechanism. Finally, the two rates interchanged spontaneously over several days without any significant interval changes in medical therapy. These findings were initially explained as probable digoxin toxicity. The underlying mechanism, however, was more likely atrial flutter with exit block and in this patient may have represented another facet of her sick sinus syndrome. This unusual phenomenon is discussed in terms of previous reports and possible implications for the mechanism of atrial flutter.

Cardiomyopathic syndrome caused by coronary artery disease. III: Prospective clinicopathological study of its prevalence among patients with clinically unexplained chronic heart failure.

Each day, for one year, the medical records of adult patients who died in hospital were reviewed before seeing the necropsy findings. For those patients who had had chronic left or left and right heart failure, a presumptive cause was assigned on the basis of antemortem clinical data. Of 740 consecutive patients who were studied at necropsy, 90 had had chronic heart failure. In 15 patients the cause of heart failure was not apparent by clinical criteria; of these, 7 were found at necropsy to have cardiomyopathic syndrome caused by coronary artery disease. In retrospect, the presence of overt diabetes mellitus was a clue that cardiomyopathy caused by coronary artery disease was the cause of clinically unexplained heart failure; 5 of 7 patients with unexplained heart failure who were found to have this at necropsy were diabetic, whereas only 1 of the other 8 patients with clinically unexplained heart failure was diabetic (P less than 0.05). Patients in whom clinically unexplained heart failure was found to be the result of cardiomyopathy caused by coronary artery disease had multiple myocardial infarctions on pathological examination, which, with one exception, were nontransmural. By contrast, myocardial infarctions were transmural on pathological examination in each of 7 matched 'controls' with heart failure, in whom the diagnosis of coronary artery disease had been clinically apparent (P less than 0.01).

The risk of advanced heart block in surgical patients with right bundle branch block and left axis deviation.

The risk of advanced atrioventricular block during anesthesia was studied prosepctively in 44 patients with right bundle branch block and left axis deviation who underwent a total of 52 operations over a 14 month period. All patients had continuous electrocardiographic monitoring throughout anesthesia induction, operation, and surgical recovery. Of the 52 operative procedures, 24 were done under general anesthesia, 11 under spinal, and 17 under local. The preoperative cardiac rhythms were atrial fibrillation in two patients, atrial tachycardia with block in one patient, atrial flutter in one patient, and sinus rhythm in the remaining patients. Temporary pacemakers were inserted preoperatively in six patients, usually because of PR interval prolongation on the preoperative electrocardiogram. There was only one episode of transient complete heart block in 51 of the 52 operative procedures. In two of the six patients with temporary pacemakers, significant pacer-related ventricular irritability occurred. This study indicates that temporary pacemaker insertion is rarely required in patients with chronic right bundle branch block and left axis deviation who require noncardiac surgery.