Effect of collateral vessels on prognosis in patients with one vessel coronary artery disease

The prognostic implications of coronary collateral channels were examined in 359 medically treated patients with one vessel coronary artery disease and a normal left ventricular ejection fraction (greater than or equal to 50%). There were 149 patients with isolated left anterior descending coronary artery disease (group I) and 210 patients with isolated left circumflex or right coronary artery disease (group II). Collateral channels were present in 68 patients (46%) in group I and 115 patients (55%) in group II. During a follow-up period of up to 82 months (mean +/- SD 34 +/- 18), there were 23 cardiac events (4 patients died of cardiac causes and 19 patients had a nonfatal acute myocardial infarction). Actuarial survival analysis showed that the risk of cardiac events was not related to the presence of collateral channels in the two groups. Thus, the risk of cardiac events is not related to the presence or absence of collateral channels in patients with one vessel coronary artery disease. Further, the risks of cardiac death (0.3%/yr) and nonfatal myocardial infarction (1.9%/yr) are very low in medically treated patients with one vessel coronary artery disease and a normal left ventricular ejection fraction.

Forward ejection fraction: a new index of left ventricular function in mitral regurgitation

Previous studies have shown that a normal LVEF is not a reliable index of LV function in MR. We hypothesized that the forward EF, which is the forward stroke volume (measured by Fick or thermodilution) divided by end-diastolic volume (measured by contrast ventriculography) may be a useful index of LV function, since it represents LV emptying into the aorta. This index was examined in 54 patients with chronic MR who had normal EF (greater than or equal to 50%). There were significant correlations between the forward EF and the end-diastolic volume index (r = -0.69, p less than 0.001), end-systolic volume index (r = -0.64, p less than 0.001), cardiac index (r = 0.43, p less than 0.01), and the ratio of systolic pressure-to-end-systolic volume (r = 0.65, p less than 0.001). Patients were divided into two groups according to the forward EF: group I (n = 34) had forward EF less than or equal to 35%; and group II (n = 20) had forward EF greater than 35%. Of the 32 patients who subsequently underwent mitral valve replacement, 24 patients were in group I and eight patients were in group II. At a mean follow-up of 35 months, four patients died; all of them were in group I. Improvement in functional class occurred in 75% of surgical survivors (80% in group I and 63% in group II, p = NS). These preliminary data suggest that forward EF may be a useful index of LV performance in patients with MR who have normal EF.

Usefulness of electrophysiologic testing in evaluation of amiodarone therapy for sustained ventricular tachyarrhythmias associated with coronary heart disease

The prognostic importance of electrophysiologic studies in patients with sustained ventricular tachyarrhythmias treated with amiodarone was prospectively studied in 100 consecutive patients. Sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) was inducible in all patients before amiodarone therapy. After amiodarone administration 2 groups of patients were identified. In group 1 patients the ventricular tachyarrhythmia was no longer inducible and in group 2 patients the arrhythmia remained inducible. In group 1, no recurrent arrhythmia occurred during a follow-up of 18 +/- 10 months. In group 2, 38 of 80 patients (48%) had arrhythmia recurrence during a follow-up of 12 +/- 9 months. The difference between group 1 and 2 could not be explained by clinical variables, amiodarone doses or plasma concentrations, or electrocardiographic variables. In patients in whom cardiovascular collapse or other severe symptoms where noted during electrophysiologic study after amiodarone treatment, recurrences caused sudden death (n = 12). However, in patients in whom the induced arrhythmia produced moderate symptoms, the recurrent arrhythmia was nonfatal VT (n = 26). Electrophysiologic testing provides clinical guidance and predicts prognosis in patients treated with amiodarone as it does for the evaluation of other antiarrhythmic agents.

Percutaneous left heart catheterization and coronary arteriography with and without an arterial sheath in patients without peripheral vascular disease

The advantages and disadvantages of an arterial sheath to introduce catheters percutaneously through the femoral artery were prospectively studied in 184 consecutive patients without peripheral vascular disease undergoing routine diagnostic left heart catheterization and coronary arteriography. The arterial sheath was used randomly in 91 patients (sheath group) and the standard Seldinger technique in 93 (control group). There were no differences in age or sex between the two groups. All patients were studied with no premedication and had the same dose of lidocaine local anesthesia and heparin. No major complication occurred in any of the patients in the sheath or control groups. There were no significant differences in groin hematomas between the two groups. The patients in the control group more commonly had severe or moderately severe discomfort requiring additional local anesthesia. We conclude that the use of an arterial sheath percutaneously for introduction of catheters for left heart catheterization and coronary arteriography is advisable, particularly for anxious patients who have a low pain threshold.

Tricuspid regurgitation: noninvasive techniques for determining causes and severity

Tricuspid regurgitation is often not apparent on physical examination and several methods are now available to aid in this difficult assessment. Cardiac catheterization using right ventriculography, previously considered the diagnostic standard, has several limitations. Currently available noninvasive tools such as M-mode and two-dimensional echocardiography (with or without contrast), Doppler techniques and even radionuclide cardiologic imaging have added significantly to the precise assessment of the presence and severity of tricuspid regurgitation. This review examines the comparative use and limitations of these various techniques.

Candida parapsilosis endocarditis without predisposing cause

Fungal endocarditis has become increasingly frequent in the past decade and invariably occurs in association with predisposing factors. We report a case of Candida parapsilosis in a patient with no predisposing cause.

Correlation between changes in R wave amplitude and left ventricular volume induced by rapid atrial pacing

To examine the Brody effect in humans, we studied 15 patients by means of coronary sinus pacing. We measured left ventricular (LV) volumes from the cardiac output (measured by the thermodilution technique) and LV ejection fraction (measured by radionuclide ventriculography). Pulmonary blood volume was determined by means of cardiac output and mean pulmonary transit time. In six patients, pacing was performed at two different rates, resulting in 21 pacing measurements. The heart rate increased with pacing from 73 +/- 11 to 119 +/- 19 bpm (mean +/- standard deviation, p less than 0.001). The end-diastolic volume (EDV) and the end-systolic volume (ESV) decreased with pacing (p less than 0.001 each). The R wave amplitude decreased with pacing (1.44 +/- 0.63 mV control vs 1.32 +/- 0.58 mV with pacing; p less than 0.01). R wave amplitude decreased in 19 of the 21 pacing studies (90%); EDV and ESV decreased in all 21 pacing studies, and pulmonary blood volume decreased in 14 of the 15 pacing studies (93%) performed in 11 patients. There was a significant correlation between the percentage of change in R wave amplitude with the percentage of change in EDV (r = 0.54, p less than 0.01) and with the percentage of change in ESV (r = 0.54, p less than 0.01). These results, therefore, validate Brody's hypothesis and indicate that changes in LV volumes affect the R wave amplitude.

Rapid progression of coronary stenosis in patients with unstable angina pectoris selected for coronary angioplasty

We studied the course of coronary stenosis in the first 62 patients (45 men and 17 women) referred for coronary angioplasty in the interval between the diagnostic arteriogram and the preangioplasty coronary arteriogram. In 42 patients, the stenosis was in the left anterior descending artery, in 17 patients in the right coronary artery, in one patient in the left circumflex, and in two patients in the vein graft. Twenty-six patients had stable angina pectoris, 34 patients had unstable angina, and two patients had no angina. The coronary stenosis did not change significantly in any patient with stable angina. Conversely, the stenosis progressed in nine of the 34 patients with unstable angina (26.5%). In five of the nine patients with progression, total occlusion ensued. In four of the five patients total occlusion occurred within the 45-day interval between the diagnostic and the preangioplasty coronary arteriogram. New or increased preexisting collaterals to the occluded vessel developed in all five patients with total occlusion. None of these patients had clinical or electrocardiographic evidence of myocardial infarction or significant changes in ventricular function. Angiographic evidence of thrombi was seen in ten of 34 patients with unstable angina (29%). We concluded that coronary artery stenosis in patients with unstable angina pectoris is progressive in a significant number after a short time. The cause of progression of coronary stenosis in patients with unstable angina is unknown. Since in a significant number of patients with unstable angina coronary thrombus was suggested by angiography, coronary thrombosis superimposed on coronary atherosclerosis may play a significant role in this syndrome. Further prospective studies are needed, including repeat coronary arteriograms to evaluate the cause of unstable angina, define the role of coronary thrombosis, and evaluate the cause of unstable angina, define the role of coronary thrombosis, and evaluate the efficacy of more aggressive treatment adding the use of prolong heparin and antiplatelet agents prior to coronary angioplasty.

Assessment of the myocardial perfusion pattern in patients with multivessel coronary artery disease

We studied 42 symptomatic patients with coronary artery disease involving two or three vessels using exercise thallium-201 myocardial scintigraphy. Qualitative analysis of the images predicted multivessel disease in 75% of the patients with two-vessel disease and in 82% of the patients with three-vessel disease. Quantitative analysis of the size of the perfusion defect indicated that approximately 40% of the left ventricular perimeter showed abnormal perfusion pattern during stress in these patients, and there was no significant difference in the size of the defect in patients with two-vessel disease or three-vessel disease (41 +/- 17% vs 42 +/- 14%, respectively, mean +/- SD). The exercise heart rate, exercise ECG response, and severity of narrowing did not correlate with the size of the perfusion defect. Patients with anterior infarction had larger defects in the distribution of the left anterior descending artery than those without infarction. Collaterals offered partial protection during exercise only when they were not jeopardized. This study confirms the value of qualitative analysis of exercise thallium-201 imaging in predicting multivessel disease, and describes a simple method of assessing the extent of perfusion abnormalities during stress in patients with multivessel disease. The results may be important in patient management and prognosis.

Noninvasive evaluation of normal and abnormal prosthetic valve function

Noninvasive techniques are helpful in evaluating the function of mechanical prostheses and tissue valves. Combined phonocardiography and M-mode echocardiography together with cinefluoroscopy are the most useful noninvasive techniques in differentiating normal from abnormal metallic prosthetic valve function. The intensity of the opening and closing clicks and associated murmurs will depend on the type of prosthetic valve, the heart rate and rhythm and the underlying hemodynamic status. Arrhythmias or conduction disturbances, or both, may produce motion patterns that mimic some of the echocardiographic signs of malfunctioning prosthetic valves. Differentiation of thrombus formation or tissue ingrowth from paravalvular regurgitation or dehiscence is possible by noninvasive techniques. Disc variance, a potentially serious and lethal problem with the older Beall valves, can be readily detected by cinefluoroscopy and echophonocardiography. With regard to bioprosthetic valves, two-dimensional echocardiography is superior to M-mode echocardiography in detecting primary valve failure. In addition, detection of vegetations, valve alignment and ring and individual leaflet motion can be best accomplished by two-dimensional echocardiography. Of greater importance is the patient serving as his or her own control in the follow-up assessment of prosthetic valve function by noninvasive techniques.

Evaluation of left ventricular function by radionuclide angiography during exercise in normal subjects and in patients with chronic coronary heart disease

Radionuclide angiography permits evaluation of left ventricular performance during exercise. There are several factors that may affect the results in normal subjects and in patients with chronic coronary heart disease. Important among these are the selection criteria: age, sex, level of exercise, exercise end points, ejection fraction at rest and effects of pharmacologic agents. An abnormal ejection fraction response to exercise is not a specific marker for coronary heart disease but may be encountered in other cardiac diseases. In addition to the diagnostic considerations, important prognostic data can be obtained. Further studies are needed to determine the prognostic implications of anatomic findings versus the functional abnormalities induced by exercise in patients with coronary artery disease.

Total occlusion of left main coronary artery without angina pectoris

A patient had total occlusion of the left main coronary artery that was proved by coronary arteriography. The patient was initially seen with clinical signs of congestive heart failure but without symptoms of angina pectoris or ECG evidence of myocardial infarction. The patient's extensive right-to-left coronary artery collaterals may have contributed to the absence of chest pain. Because of the severe left ventricular dysfunction and the absence of chest pain, the patient was treated with medical therapy. Six months after the cardiac catheterization, he was alive and well under New York Heart Association functional classification II.