Cardiologic manpower resources and their distribution: a challenge for the future.

All of us have some familiarity with the cardiology manpower study that has been published.¹ The results of this study must in large measure serve as the data base for the deliberations of this Symposium and for our planning for the future. Let me start, therefore, with a rather selective overview of the data pertinent to our task. Let us remember that, although I shall use the present tense, the data base refers to 1972–1973.     

Treatment of preinfarction angina with intraaortic balloon counterpulsation and surgery

Sixteen patients with preinfarction angina unresponsive to medical therapy were treated by Counterpulsation with the intraaortic balloon pump. Chest pain and electrocardiographic changes were abolished or significantly decreased in all but one patient. Counterpulsation reduced peak systolic blood pressure, but had little effect on pulmonary capillary wedge pressure or cardiac output. Coronary anatomy was then defined by coronary angiography. Significant obstructive atherosclerosis of the main left or left anterior descending coronary artery was present in all but one patient. All patients underwent coronary revascularization by saphenous vein aortocoronary bypass graft. Fifteen of 16 patients survived the operation. All survivors are clinically improved, and 13 are completely asymptomatic from 1 to 20 months postoperatively.     

Sustained effect of orally administered isosorbide dinitrate on exercise performance of patients with angina pectoris.

The efficacy of oral isosorbide dinitrate was evaluated in nine hospitalized patients with chronic angina pectoris and positive maximal bicycle exercise tests. Patients were randomized double-blind to receive either 20 mg of isosorbide dinitrate or placebo on successive days after a control maximal upright bicycle exercise test. On each day hourly exercise tests were performed for 4 hours after drug administration to an end point of fatigue or angina pectoris. Mean systolic blood pressure 4 hours after the administration of isosorbide dinitrate was 25 mm Hg less than the control value (P less than 0.001). The values for resting heart rate and exercise-attained heart rate-blood pressure product were not significantly different from the values after placebo. The duration of exercise was prolonged (P less than 0.025) for at least 3 hours, and less ST depression (P less than 0.01) was observed up to 3 hours after the administration of isosorbide dinitrate compared with control values. The demonstration of sustained imporved exercise performance and previously described hemodynamic effects with the use of higher doses suggests that adequate blood levels of isosorbide dinitrate or mononitrate metabolites may be important for the efficacy of oral organic nitrates.     

Occurrence and reproducibility of exercise-induced ventricular ectopy in normal subjects

The prevalence of ventricular ectopy was determined during gymnasium exercise in 289 normal men and 56 normal women. Ventricular ectopy was detected in 35 percent of men and 14 percent of women. Prevalence increased with age from 18 percent positive responses in men under 30 to 50 percent over 50 years; men had more ectopy than women at each decade of life. Cigarette smoking, coffee drinking and regular physical activity had no significant impact on the prevalence of ventricular ectopy. The first 38 men with ventricular ectopy during the screening were recruited for additional tests of prevalence and reproducibility. The prevalence of ventricular ectopy increased from 15 percent at a heart rate of less than 120 beats/min to 50 percent at a rate of more than 150 beats/min. Ventricular ectopy occurred 2.5 times more frequently during the exercise than the recovery periods, and examination of both periods increased the yield over exercise alone by 1.2 times. At similar heart rates, the prevalence levels of positive tests (both exercise and recovery periods) were the same during running as during ergometric exercise. The prevalence of ventricular ectopy was not significantly different in patients after myocardial infarction than in normal persons matched for age and heart rate (42 and 36 percent, respectively). During two sessions of gymnasium exercise at similar heart rates (within 10 beats), there were 21 percent positive results on the first test and 19 percent positive results on the second (not significantly different). Positive results were reproduced in 64 percent of cases. Reproducibility was the same at all heart rates and was slightly better during exercise than during recovery periods. This regularly exercising population had a noteworthy prevalence of ventricular ectopy and the results were reproducible in a high proportion of cases.     

Angioinvasive pulmonary aspergillosis: presentation as massive pulmonary saddle embolism in an immunocompromised patient

A 33 year old woman with chronic myelogenous leukemia presented with clinical symptoms and hemodynamic signs suggestive of pulmonary embolism. Initial angiographic studies supported the diagnosis of a massive saddle pulmonary embolus, and an inferior vena cava filter was inserted. However, subsequent autopsy revealed unsuspected angioinvasive pulmonary aspergillosis with secondary in situ thrombosis. The clinical features and diagnostic considerations in immunocompromised patients presenting with the clinical picture of pulmonary embolism are discussed.     

Coronary angioscopy during cardiac catheterization

Coronary angioscopy should permit direct inspection of the luminal cross section and identification of disease. The feasibility of introducing a 5F Olympus Ultrathin fiberscope into the obstructed right coronary artery in five patients after routine cardiac catheterization by the brachial approach was therefore tested. An 8.3F USCI woven Dacron angioplasty guiding catheter was modified to enlarge its lumen. After engaging the right coronary ostium with the catheter, an attempt was made to pass the angioscope coaxially to the tip of the catheter. Visualization of the coronary lumen was then achieved in three patients by manually injecting 5 to 10 cc of normal saline solution through the guiding catheter at 2 to 3 cc/s. White atheromatous plaque could be seen near the site of obstruction in each case. In two patients, a lack of sufficient flexibility in the distal 2 cm of the angioscope prevented passage to the catheter tip. Preliminary experience with a videoendoscopic system suggests that this monitoring technique is essential for the adequate performance of angioscopy and for recording dynamic changes during blood displacement. Geometric distortion of the image and nonlinearities in magnification and light reflex with a decreasing lens to object distance make quantitative evaluation of the lumen difficult. Lack of an angulation system further contributes to this problem and, more importantly, restricts passage of the angioscope to the proximal 1 to 2 cm segments of coronary arteries. Although coronary angioscopy may have research and clinical applications in the future, these technical problems should first be addressed.     

Q-aTc interval as a clinical indicator of hypercalcemia.

The charts were reviewed of more than 200 patients discharged from the hospital between 1972 and 1977 with a diagnosis implying abnormal calcium metabolism. When all other variables known to affect the Q-T interval were eliminated, serum calcium concentrations on 65 occasions in 39 patients were found to correlate significantly (P less than 0.001 or better) with the following electrocardiographic intervals: Q-aTc (beginning of QRS complex to apex of T wave), Q-oTc (beginning of QRS complex to onset of T wave) and Q-Tc (beginning of QRS complex to end of T wave). Of these, the Q-aTc interval was the more easily and precisely measured at elevated calcium levels and exhibited the strongest correlation (P less than 0.0001) over the range of calcium levels measured. The relation was linear and could be used to estimate serum calcium levels from measured Q-aTc intervals. For a Q-aTc interval of 0.29 second or less (range 0.23 to 0.29) the serum calcium was estimated to +/- 1.9 mg/dl with 95 percent confidence. For a Q-aTc interval of 0.27 second or less, the correspondence with hypercalcemia in the study series was 90 percent or better. When all other factors known to affect the Q-T interval are ruled out, the shortening of the Q-aTc interval appears to be a useful clinical indicator of hypercalcemia.     

Disappearance of bundle branch block with slowing of normal heart rate

Four patients are presented with varied mechanisms of converting bundle branch block to normal ventricular conduction with slowing of normal heart rate. One patient had a relatively constant range of critical heart rates for left bundle branch block, incomplete left bundle branch block, and normal conduction during a three-year period of observation.This report emphasized that bradycardia-dependent normalization of bundle branch block is not uncommon.     

Flow murmur associated with partial occlusion of the right pulmonary artery.

An 18-year-old male student presented with a brief history of syncope followed by shortness of breath with exertion, and the development of murmur over the right chest. The symptoms and murmurs were related to a pulmonary embolus which partially occluded the right pulmonary artery and its major branches. The murmur gradually diminished and disappeared when right pulmonary perfusion had almost returned to normal as determined by lung scan. The association of pulmonic flow murmurs and pulmonary emboli is reviewed.     

Catheter-induced arrhythmias

Catheter-induced arrhythmias, which occurred several hours to several days following successful placement of temporary transvenous right ventricular electrodes or flow-directed pulmonary artery catheters were observed in six out of 106 patients. The arrhythmias took the form of ventricular bigeminy, ventricular tachycardia and, in one instance, isorhythmic dissociation. These arrhythmias were resistant to high doses of antiarrhythmic medication. The diagnosis can be suspected by noticing an excessive catheter loop or an altered catheter position in the chest x-ray or by observing faulty sensing, erratic pacing, or an increased threshold for ventricular stimulation. Corroborative evidence can be obtained from the electrocardiogram, where the catheter-induced depolarizations usually take a left bundle branch block pattern and the coupling interval of the ectopic beats may vary widely. Some pacing catheter-induced beats resemble the paced beats in configuration. In other cases, the rhythm cannot be explained by established principles. The diagnosis of catheter-induced arrhythmia is confirmed when the arrhythmia ceases following removal or repositioning of the catheter.     

Two dimensional echocardiography in differentiating right atrial and tricuspid valve mass lesions.

Atrial myxoma has been diagnosed on the basis of a characteristic M mode echocardiographic pattern of a mass of echoes appearing, with a lag phase, beneath the anterior leaflet of the mitral or tricuspid valve in diastole. However, this pattern is not specific for an atrial tumor. Two patients are described with tricuspid leaflet endocarditic vegetations whose M mode echocardiograms were strikingly similar to the M mode tracing from a patient with a large right atrial myxoma. In a fourth patient, artifact, resulting from the failure of lateral resolution of the atrial wall, was also capable of producing a mass of echoes appearing, with a lag phase, beneath the anterior tricuspid valve leaflet in diastole. In each patient, two dimensional echocardiography confirmed the presence or absence of a right-sided mass lesion and defined more precisely the location of the echocardiographic density relative to the right atrium and tricuspid valve. Because two dimensional echocardiography is capable of detecting anatomic relations in two distance dimensions and of visualizing movement of intracardiac structures relative to one another in real time, it can play an important role in the identification and differential diagnosis of intracardiac mass lesions.     

Comparison of the effects of nitroprusside and nifedipine on diastolic properties in patients with hypertrophic cardiomyopathy: Altered left ventricular loading or improved muscle inactivation?

The calcium channel blocking agent, nifedipine, has been shown to improve indexes of left ventricular relaxation, diastolic filling and compliance in patients with hypertrophic cardiomyopathy. The mechanism of action of nifedipine on diastolic properties in patients with hypertrophic cardiomyopathy is unclear and could result from an improvement in myocardial inactivation or from systemic vasodilation and left ventricular unloading. To distinguish between these mechanisms, the effects of nifedipine and the vasodilator nitroprusside on left ventricular diastolic properties were compared in 10 patients with nonobstructive hypertrophic cardiomyopathy using simultaneous micromanometer left ventricular pressure and echocardiographic measurements. Left ventricular peak systolic pressure was comparable during nitroprusside infusion (132 +/- 38 mm Hg) and after nifedipine (132 +/- 32 mm Hg). During nitroprusside infusion, the decrease in left ventricular end-diastolic pressure (22 +/- 11 to 17 +/- 11 mm Hg, p less than 0.05) was associated with a decrease in left ventricular end-diastolic dimension. In contrast, the decrease in left ventricular end-diastolic pressure after nifedipine (22 +/- 11 to 18 +/- 10 mm Hg, p less than 0.05) was associated with no reduction of left ventricular end-diastolic dimensions, suggesting an increase in left ventricular distensibility. Compared with nitroprusside, nifedipine was associated with less prolongation of the left ventricular isovolumic relaxation time and less depression of the peak left ventricular posterior wall thinning rate and peak left ventricular internal dimension filling rate. These data suggest that the effects of the calcium channel blocker, nifedipine, on diastolic mechanics in hypertrophic cardiomyopathy result not only from systemic vasodilation but also from improved cardiac muscle inactivation.     

Improved cross-sectional echocardiographic technique for visualization of the retrocardiac descending aorta in its long axis. Normal findings and abnormalities in saccular and/or dissecting aneurysms

The feasibility of using an improved ultrasonic technique for visualization of the retrocardiac descending thoracic aorta was studied in 50 consecutive patients. Both anterior and posterior aortic walls were well delineated in long as well as short axis in 92%. The mean length of the visualized portion of the retrocardiac aorta was 8.4 cm (range 4.5 to 13) and exceeded 6 cm in 40 of 46 patients. The mean diameter was 2.0 cm (range 1.3 to 2.7). Five patients with saccular (1 patient) and/or dissecting (all 5 patients) aneurysms involving the retrocardiac aorta were also examined. Abnormalities essentially identical to those seen with computerized tomography and aortography were noted. Intimal flaps were visualized by ultrasound in all 5 patients and were seen to oscillate reproducibly with the cardiac cycle, suggesting differential rates of filling of false and true lumens. This and other previous cross-sectional echocardiographic studies of the ascending aorta suggest that ultrasound may be useful in the initial evaluation of patients presenting with symptoms or signs suggestive of acute or chronic aortic disease.     

Medically refractory unstable angina pectoris. I. Long-term follow-up of patients undergoing intraaortic balloon counterpulsation and operation.

Of 82 patients with medically refractory unstable angina pectoris seen between October 1972 and January 1978, 60 patients underwent a combination of intraaortic balloon pump counterpulsation, cardiac catheterization and coronary revascularization. Most patients had atherosclerotic involvement of the vessels of the anterior left ventricular wall, 48 patients (80 percent) had abnormalities of left ventricular wall contraction and 22 patients (36 percent) had evidence of acute myocardial injury. One operative and one late death occurred. The perioperative infarction rate was 5 percent. Survivors, followed up for 3 to 63 months (mean 31 months), have done remarkably well; 77 percent are considered employable,and more than 90 percent are in functional class I or II.     

M mode and cross-sectional echocardiographic recognition of fibrosis and calcification of the mitral valve chordae and left ventricular papillary muscles

The echocardiographic appearance of fibrotic thickening and calcification of mitral valve chordae tendineae and left ventricular papillary muscles in 17 patients is described. Pathologic proof of excessive fibrosis or calcification was obtained in five patients. In a sixth patient, calcium was demonstrated on angiography to extend from the chordae into papillary muscle. The characteristic feature of chordal and papillary muscle fibrosis and calcification is the presence of highly echogenic densities best visualized within the left ventricle at a level below the mitral valve leaflets. The more inferior location of these densities, within the body of the left ventricle, enables them to be easily differentiated from densities indicating fibrosis and calcification of the mitral valve anulus.The pattern of chordal and papillary muscle fibrosis and calcification was frequently associated with mitral anular calcification, aortic valve fibrosis or calcification and left atrial enlargement. One patient had rheumatic mitral valve disease. Many patients had mitral regurgitation and most had a history, physical examination and radiologie findings compatible with congestive heart failure. Although the origin and importance of the chordal and papillary muscle changes reported are not known, their frequent association with mitral regurgitation and with congestive heart failure suggests possible interrelations.     

Medically refractory unstable angina pectoris. II. Hemodynamic and angiographic effects of intraaortic balloon counterpulsation.

Of 60 patients receiving intraaortic balloon counterpulsation for angina refractory to maximal medical therapy, a subgroup of 10 patients underwent left ventricular angiography both with and without counterpulsation. Severe stenosis of the left anterior descending coronary artery was present in all 10 patients. Counterpulsation resulted in a significant decrease in systolic and end-diastolic left ventricular pressures and no increase in cardiac index. Left ventricular diastolic and systolic volume, ejection fraction and regional contraction patterns, often abnormal, were unchanged. However, mean normalized systolic ejection rate was improved by the addition of counterpulsation. It is concluded that intraaortic balloon counterpulsation has relatively little effect on the left ventricular volume of patients with medically refractory angina pectoris. The symptomatic improvement that takes place seems to occur mainly through the effect of counterpulsation on preload and afterload.