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A frequent long-term complication of bioprosthetic valves is spontaneous degeneration of the cusps with clinical features of valve regurgitation or, less frequently, valve stenosis.1 Transthoracic echocardiography with cardiac Doppler is valuable in diagnosing stenosis of bioprosthetic valves.2 However, a major drawback of this approach is that all 3 bioprosthetic cusps are not consistently demonstrated owing to sound attenuation from the intervening chest wall and lungs, and to reverberation from the metal portion of the valve ring and stents. These problems are usually overcome by using a transesophageal ultrasound probe. We recently described our transesophageal echocardiographic investigations in predominantly regurgitant bioprosthetic valves.3 Those patients are not included in this study. To the best of our knowledge, there are no reports on stenotic bioprostheses studied by transesophageal echocardiography.

One thousand ECGs were selected from those taken from an adult population and analyzed by three cardiologists to assess the performance of the IBM Bonner-2 (V2 MO) program. The sample included 200 ECGs with 248 myocardial infarctions, 200 with conduction abnormalities, 100 with ventricular hypertrophy, 300 normals and 200 with electronic pacemakers. In the MI group, there was a total sensitivity of the program with respect to the readers of 88% (218/248) with 19 (8%) program errors and 90% (248/275) specificity. In 53 ECGs with two MI statements, the sensitivity was 89% (47/53). The sensitivity in conduction abnormalities was 93.4% (183/196) with 98.7% specificity (800/810). The sensitivity in LVH was 90% (74/81) and in RVH 83% (5/6). Among the normals, the specificity was 98.6% (289/293). The sensitivity to PVCs was 84% (56/67), to atrial fibrillation 87% (48/55), to SVCs 58.6% (17/29) and to electronic pacemakers 65% (127/196). Recognizing the limitations of this type of analysis, this study indicates that the V2 MO version compares favorably with the earlier versions of the same program and is a valuable aid in ECG interpretation with rapid acceptance by physicians.

Echophonographic findings of three patients with spontaneous degeneration of porcine tricuspid and mitral valves presenting with musical murmurs are reported. Echocardiography in all these patients revealed systolic or diastolic cusp flutter similar in frequency to the musical murmur on simultaneously recorded phonocardiogram. Porcine tricuspid regurgitation is usually well tolerated and can be followed clinically for many years. However, patients with mitral porcine valves usually become symptomatic or present with congestive heart failure and usually require valve surgery soon after clinical or echo-phonocardiographic findings of valve regurgitation appear.

Direct involvement of the myocardium, a serious complication of sarcoidosis, was observed in 2 cases. The first patient had a progressively downhill course over 2 1 2 years, ending in sudden death. Her disease was characterized by recurrent ventricular arrhythmias, progressive heart failure and terminal arrhythmia. Cardiac catheterization and cineangiocardiograms performed before death revealed 2 ventricular aneurysms. Postmortem examination revealed extensive fibrosis and typical noncaseating granulomatous infiltration of the myocardium. The second patient presented with complete heart block. At the time of implantation of an epicardial pacemaker, biopsy of the myocardium and a mediastinal lymph node showed the noncaseating granulomas of sarcoidosis. In the subsequent years, atrioventricular (A-V) conduction improved and, when last seen, the patient maintained a normal sinus rhythm with first degree atrioventricular block.

The diagnostic difficulties between supraventricular tachyarrhythmias with intraventricular conduction delay and ventricular tachycardia have challenged the physician since the first recording of a ventricular tachycardia by Lewis in 1909. 2 The examples selected emphasize some of the diagnostic and therapeutic dilemmas of "broad QRS tachycardias" and their major differential features from abberrancy. Multiple simulataneous surface ECG leads are valuable in showing the direction of the initial activation forces of the QRS complexes, the frontal QRS axis and the configuration of the QRS in lead V 1 . Vagal maneuvers and intraatrial or esophageal leads are very useful in demonstrating the underlying atrial rhythm and atrioventricular dissociation when present. In life-threatening situations, urgent therapy or D.C. cardioversion may be required before a definitive diagnosis has been established. In recent years electrode catheter techniques for the diagnosis, 12,21,22 for arrhythmia induction and for the selection and assessment of the effectiveness of the antiarrhythmic drug therapy have been carried out in the management of recurrent broad QRS tachycardia. 23 In view of the inherent risks with the use of this invasive technique, it should be restricted to a carefully selected number of patients with recurrent life-threatening dysrhythmias as suggested by Scheinman. 24

A case of left adrenal pheochromocytoma manifesting clinically as a cardiomyopathy is described. The symptoms of persistent sinus tachycardia and profuse sweating and an abnormal glucose tolerance test prompted the diagnosis, which was confirmed by the finding of increased urinary catecholamine excretion and observations at surgery. The predominant epinephrine secretion of the tumor could explain the relative normotension and abdominal cramps observed in this patient. Marked improvement in the hemodynamic findings and disappearance of the symptoms of congestive heart failure after removal of the tumor are supportive evidence of an underlying catecholamine-induced “myocarditis.”

Synchronized direct countershock, introduced by Lown et al 1 in 1962, is generally accepted as the treatment of choice for the rapid termination of atrial flutter. 2 In 1967, Haft and associates 3 first applied the technique of rapid atrial pacing in the treatment of atrial flutter, and its use was found to be safe even in patients with digitalis-excess. 4,5 Induction of atrial fibrillation has been initiated successfully with a variety of temporary pacemaker methods in the management of supraventricular tachycardias, 6 including atrial flutter. 7 On occasion, patients are encountered who, as a result of unresponsiveness to the intensive medical treatment 8 or intolerance to available antiarrhythmic drugs, continue to experience frequent bouts of atrial tachyarrhythmia. This is accompanied by markedly disabling and even lifethreatening symptoms making the application of other more definitive forms of therapy, such as the surgical induction of atrioventricular (AV) block and ventricular pacing