Harold T. Mankin

Spontaneous Calcific Embolization Associated with Calcific Aortic Stenosis

The problem of spontaneous calcific embolization was investigated at necropsy in 165 patients with calcific aortic stenosis. Minor coronary arteries contained calcific emboli in 18 patients (11 per cent), and major coronary arteries contained calcific emboli in 10 (6 per cent). Examination of the brain, kidney, and eye also disclosed spontaneous calcific emboli. In three instances of major coronary artery embolization, there was evidence of old silent infarction but no associated clinical disorder. Calcific embolization is apparently not rare in cases of calcific aortic stenosis, but this phenomenon does not appear to lead very often to extensive infarction or to clinically obvious disorders.

Anatomic and functional significance of a hypotensive response during supine exercise radionuclide ventriculography.

The significance of a decline in systolic blood pressure (BP) during supine exercise was examined in 820 patients who underwent both supine exercise gated equilibrium radionuclide ventriculography and coronary angiography. Twenty-seven patients, 3% of the study population, had a decrease in systolic BP at peak exercise of more than 10 mm Hg from the systolic BP at rest. Other indicators of ischemia--angina, ST-segment depression, a decrease in ejection fraction and wall motion abnormality during exercise--were present frequently but not uniformly in these patients. Although most patients had a decline in ejection fraction and a new wall motion abnormality with exercise, 4 patients had an increase in ejection fraction with exercise without any regional wall motion abnormalities. Coronary angiography in the 27 patients with systolic hypotension demonstrated severe coronary artery disease (CAD). Twenty-two patients (81%) had 3-vessel or left main CAD. Twenty of these 22 patients with 3-vessel CAD had at least 2 arteries with 90% or more diameter stenoses. Systolic hypotension during supine exercise radionuclide angiography is infrequent, usually associated with evidence of global and regional left ventricular dysfunction, and a marker of very severe CAD.

Value of the resting 12 lead electrocardiogram and vectorcardiogram for locating the accessory pathway in patients with the Wolff-Parkinson-White syndrome.

The resting 12 lead electrocardiogram and vectocardiogram were reviewed in 47 patients with the Wolff-Parkinson-White syndrome (a) who had pre-excitation on the resting 12 lead electrocardiogram, (b) who had a single anterograde conducting accessory pathway assessed and located during preoperative electrophysiological study and during epicardial mapping at operation, and (c) in whom surgical division of the accessory pathway resulted in loss of pre-excitation. The site of the accessory pathway established during operation was compared with that established by evaluating the polarity of the delta wave and QRS complex on the resting 12 lead electrocardiogram. The electrocardiogram was assessed by the Rosenbaum criteria (Wolff-Parkinson-White type A, left-sided pathway; or type B, right-sided pathway), the Gallagher criteria (atrial pacing resulting in maximal pre-excitation), and the World Health Organisation criteria (a composite of previous studies). The Gallagher and World Health Organisation criteria were derived from patients demonstrating maximal pre-excitation that often required atrial pacing. The present study was designed to determine whether these criteria could be accurately applied to the resting 12 lead electrocardiogram on which the degree of pre-excitation was variable. The Rosenbaum criteria correctly identified a left sided accessory pathway in 26 of 34 patients and a right-sided accessory pathway in nine of 13 patients. The Gallagher and World Health Organisation criteria correctly identified the location in only 15 (32%) of the 47 patients. The resting vectorcardiogram was inaccurate for locating the accessory pathway. Although published criteria are useful for identifying the site of the accessory pathway from an electrocardiogram obtained when rapid atrial pacing is being used to achieve maximal pre-excitation, they are not suitable for identifying the exact site of an accessory pathway from the resting 12 lead electrocardiogram.

Calcific Embolization Associated with Valvotomy for Calcific Aortic Stenosis

Calcific emboli were observed in 38 of 62 patients (61 per cent) who died at varying intervals following aortic valvotomy for calcific aortic stenosis. Major coronary embolization occurred in 10 patients (16 per cent) and was considered to be a major cause of death of four patients. Minor coronary embolization occurred in 33 patients (53 per cent) and was not directly implicated as a cause of death in any patient. Calcific emboli occurred to other organs in eight patients (13 per cent). The technics instituted for reducing the incidence of embolization—occlusion of coronary ostia, diligence in detection and removal of any debris, and final aspiration of the left ventricle—appeared to have had a favorable effect.

Temporary Transvenous Catheter-Electrode Pacing of the Heart

Experience with 110 separate periods of transvenous cardiac pacing by means of a catheter-electrode in 91 patients has been reviewed. Indications for the use of the catheter-electrode included (1) complete heart block with and without Adams-Stokes syndrome, (2) other arrhythmias with and without cardiogenic syncope, (3) malfunction of previously implanted permanent pacemaker units, and (4) need for pacing during general surgical procedures in patients with a variety of rhythm disturbances. A case illustrating the combined use of drug therapy and catheter-electrode pacing in controlling paroxysmal ventricular tachycardia is presented.Only six deaths occurred in spite of the serious heart disease in all 91 patients in this series. Two were related to complications of temporary transvenous intracardiac pacing. The major complications associated with the procedure included perforation of the heart, bacteremia, acute myocardial infarction, cephalic vein phlebitis, and ventricular tachyarrhythmia. Minor problems were primarily related to equipment failure or positional difficulties with the catheter-electrode and were usually of no serious consequence.

Guidelines for the interpretation of the exercise radionuclide ventriculogram for diagnosing coronary artery disease

In 622 patients with known coronary artery anatomy, heart rate (HR).blood pressure (BP) product and left ventricular (LV) ejection fraction (EF) at maximal supine exercise measured by radionuclide ventriculography were used to estimate, by logistic regression analysis, the probabilities of absence of significant coronary artery disease (CAD), presence of significant CAD, presence of multivessel CAD and presence of 3-vessel CAD. Thus, for example, estimated probabilities of each of the aforementioned 4 categories of CAD are 0.39, 0.61, 0.32 and 0.12, respectively, for HR.BP product of 26,000 beats.mm Hg/min and LVEF of 0.6 at maximal exercise and 0.08, 0.92, 0.77 and 0.48, respectively, for HR.BP of 15,000 and LVEF of 0.4. The graphic presentations of these estimated probabilities form useful guidelines for interpreting the results of exercise radionuclide ventriculography. In addition, specific cutoff values at maximal exercise defined 2 groups: (HR.BP product greater than or equal to 21,000 beats.mm Hg/min and LVEF greater than or equal to 0.55) with a high (70%) likelihood of absence of significant CAD or 1-vessel CAD and a low (7%) likelihood of 3-vessel CAD, and (HR.BP product less than 21,000 and LVEF less than 0.55) with a high (72%) likelihood of multivessel CAD and a low (8%) likelihood of absence of CAD.

The divergent recovery of ST-segment depression and radionuclide angiographic indicators of myocardial ischemia

This study evaluated the recovery after exercise of both ST-segment depression on the exercise electrocardiogram (electrical evidence of ischemia) and exercise-induced abnormalities in wall motion or ejection fraction as detected by radionuclide angiography. The study group of 31 patients was selected to undergo prolonged electrocardiographic and radionuclide imaging after exercise because they had persistent ST-segment depression greater than 3 minutes after exercise and radionuclide angiographic evidence of ischemia at peak exercise. In 27 (87%) of the 31 patients, radionuclide evidence of ischemia recovered more quickly than the electrocardiogram. Only 15 of the 31 patients had exercise-induced radionuclide abnormalities after exercise. Compared with the 16 patients without such findings of ischemia after exercise, these 15 patients had a worse wall motion score at peak exercise (5.3 vs 3.9; p less than 0.01) and a smaller increase in systolic blood pressure with exercise (p less than 0.05) and after exercise (p less than 0.01). Radionuclide angiographic evidence of ischemia recovers more quickly after exercise than ST-segment depression. When there is radionuclide evidence of ischemia after exercise, it is associated with more severe ischemia during exercise.