Conduction system in a patient with Prinzmetal's angina and transient atrioventricular block

[Exercise-induced atrioventricular block. Significance of the ischemic component. Report of 4 new cases]

We report four new cases of exercise-induced atrio-ventricular block (appearing during treadmill exercise testing). The mechanism was ischemia in two patients and the conduction disturbance disappeared after coronary artery bypass grafting. The literature on this matter is reviewed. Also the etiology, the natural history and management are discussed in these cases.

Exercise-induced syncope as late consequence of radiotherapy

This report describes a 34-year-old female with an exercise-induced atrioventricular block resulting from transient ischemia caused by a radiation-induced ostial stenosis of the right coronary artery. Patient first underwent coronary artery surgery with a right internal mammary artery to the right coronary artery. After 18 months she was readmitted with exercise-induced syncope due to graft occlusion. This time a successful rotablator procedure was performed on the ostial stenosis.

Nonatherosclerotic causes of coronary artery narrowing--Part II

Part II of this three-part article on nonatherosclerotic causes of coronary heart disease focuses on myocardial bridges, coronary artery aneurysms, emboli, coronary dissection, and spasm as causes of luminal narrowing.

Anatomy, histology, and pathology of the cardiac conduction system--Part V

Although morphologic findings in many of the cardiac arrhythmias of acute and chronic disease have been elusive, the correlates of heart block (particularly atrioventricular block) are abundant. Pathologic features of sinoatrial, atrioventricular, and bundle-branch block are reviewed. Lev and Lenegre diseases (idiopathic bilateral bundle-branch fibrosis) are also reviewed.

Exercise-related atrioventricular block. Influence of myocardial ischemia

A 62-year-old woman was noted to have complete heart block immediately following an exercise stress test. Coronary arteriography subsequently revealed a significant lesion in the right coronary artery, which was successfully dilated. Thallium-exercise testing following angioplasty showed no evidence of inducible ischemia and no arrhythmia was seen, supporting the idea that exercise-related heart block may occur secondary to myocardial ischemia.

Prinzmetal angina. Multifocal ischemia, recurrent AV block, and bradycardia with patent coronary arteries responsive to verapamil

Coronary vasospasm may result in recurrent angina pectoris and cause acute myocardial infarction. The extent to which the "sudden death syndrome" occurs is unknown. The case described herein is unique in that the clinical features, including hypotension, AV block, and ventricular arrhythmias, were similar to those seen in myocardial infarction with a poor prognosis, yet infarction was not documented. In subsequent, long-term follow-up evaluation, chest pain has been recurrent, but despite close observation, no further major cardiac complications have been documented. Long-term use of verapamil has contributed to better control of clinical symptomatology.

Perivascular nerve lesion of the coronary artery involved in spasm in a patient with variant angina

An autopsy case of a 52-year-old man with typical variant angina is reported. He had recurrent attacks of chest pain at rest, particularly from midnight to early morning, associated with ST segment elevation in the electrocardiogram. At autopsy, degenerative changes and fibrosis were confirmed light microscopically in the perivascular nerves of the coronary artery involved in spasm. This finding indicates an intimate relationship between coronary spasm and the autonomic nervous system.

Exercise-induced distal atrioventricular block

Three patients with 1:1 atrioventricular (AV) conduction at rest developed fixed 2:1 or 3:1 AV block during treadmill exercise testing. Electrophysiologic study documented block distal to the AV node in all three patients, and suggested that the exercise-induced block occurred because of increased atrial rate and abnormal refractoriness of the His-Purkinje conduction system. The findings in these three patients suggest that high grade AV block appearing during exercise reflects conduction disease of the His-Purkinje system rather than of the AV node, even in the absence of bundle branch block. Patients with this diagnosis should be considered for permanent cardiac pacing.

Sudden death in Prinzmetal's angina with coronary spasm documented by angiography. Analysis of three necropsy patients

Clinical and necropsy findings are described in three patients who had angina pectoris at rest, S-T segment elevation on electrocardiography during chest pain, coronary arterial spasm on angiography and sudden death. Although significant "fixed" coronary narrowing (that is, narrowing due to atherosclerotic plaques) was appreciated by angiography in only one of the three patients, necropsy disclosed in all three patients severe fixed coronary narrowings involving particularly the artery in which spasm had been demonstrated during life. Additionally, examination of each 5-mm long segment of the coronary artery that had been spastic during life (two patients) disclosed several focally spastic segments at necropsy, indicating that spasm persisted after death. Although most previously described necropsy patients with Prinzmetal's angina had some fixed coronary narrowing, underlying fixed narrowing may be difficult to identify angiographically as demonstrated by the three patients in this study.

Increase in R-wave amplitude during transient epicardial injury (Prinzmetal type)

An increase in QRS amplitude with S-T elevation occurs during the acute phase of myocardial infarction, coronary ligation and variant angina. Ischemic conduction delay, postulated as the cause, has not been well characterized. Six patients with transient chest pain, S-T elevation and increase in R-wave voltage also displayed concomitant shift of the frontal QRS axis toward the locus of injury. Electrocardiographic considerations suggest that regional ischemic block, not true hemiblock as has been suggested, offers the most inclusive explanation, providing previously neglected clinical confirmation of experimental observations.