Prediction of maximal cardiac output in preoperative patients with coronary artery disease.

Of 100 patients (89 men, 11 women) studied preoperatively to determine their aerobic and hemodynamic profiles at rest and during upright treadmill exercise. The mean maximal cardiac output (CO), measured using the direct Fick principle, was 57 +/- 14% of average normal values. The reduction in maximal heart rate (63 +/- 13% of normal) was a greater factor in the reduction in CO than stroke volume (88 +/- 16% of normal). Maximal oxygen consumption (VO2max) was 48 +/- 15% of normal and the greater reduction in VO2max compared with CO was due to lower peripheral extraction in the coronary patients. Variables that correlated with maximal CO in a univariate analysis included angina severity (r = -0.45), VO2max (r = 0.67), maximal heart rate (r = -0.31), left ventricular dysfunction (r = -0.45), maximal systolic blood pressure (r = -0.31) and number of vessels with greater than or equal to 50% diameter reduction (r = -0.3). Resting ejection fraction did not correlate with maximal CO. In a multivariate analysis, 4 variables correlated significantly (r = 0.77) with maximal CO: in order, VO2max, number of vessels with greater than or equal to 50% stenosis, magnitude of ST depression and sex.

Improvement in aerobic and hemodynamic responses to exercise following aorta-coronary bypass grafting.

Preoperative and postoperative hemodynamic studies were performed during exercise in 70 patients having aorta-coronary bypass grafting for the treatment of angina. There was significant symptomatic improvement with 88% of patients free of angina postoperatively. In patients with complete revascularization there was a marked improvement during exercise in maximal oxygen consumption, cardiac index, and maximal pressure-rate product. In addition, there was a fall in pulmonary arterial pressure postoperatively. In contrast, patients with incomplete revascularization showed a small but insignificant rise in maximal oxygen consumption and cardiac index. The major reason for the increase in cardiac index was a marked increase in heart rate rather than a change in stroke index. In patients with complete revascularization there was a significant increase in stroke work index at maximal exercise.

Primary chylopericardium.

In a 23-year-old man with massive chylous pericardial effusion, oral administration of Sudan III and radio-active 131iodine-labelled triolein revealed an abnormal communication between the lymphatic system and the pericardial sac. Despite partial pericardiectomy and resection of the thoracic duct, the fluid reaccumulated, and a postoperative lymphangiogram showed an obstructed left thoracic duct. Resection of this left thoracic duct resulted in full recovery. This is the first reported case of this disease with a duplicate thoracic duct. Careful attention must be paid to the possibility of this variation before and during surgery.

Aging alteration of cardiac vagosympathetic balance assessed through the tone-entropy analysis.

BACKGROUND: Age-associated alterations of cardiac autonomic functions have been investigated intensively through heart rate variability analyses. However, changes with age in cardiac vagosympathetic balance remain to be elucidated. METHODS: We studied 142 male subjects (30-69 yr) at a health care center in Kyoto, Japan. Electrocardiographic data were collected from subjects in a recumbent position for 10 min in the morning. Analysis was done by classifying the subjects into four age groups. In a pharmacological experiment carried out in December 1996, tone was verified to reflect the cardiac vagosympathetic balance, and entropy the total autonomic neural efferent activity. We assessed the heart rate variability through the tone-entropy (T-E) analysis that was described previously. In essence, two indexes, tone and entropy, were defined on a distribution of successive variations of heart period. RESULTS: No significant differences were detected in clinical conditions among the four age groups. Tone increased and entropy decreased significantly with age. The aging process was expressed as a curvilinear path in T-E space. Compared to the pharmacological experiment, it was observed that aging degenerated the heart function from an ordinary to a denervated one. The same aging path was superimposed in the opposite direction on the heart recovery path after dynamic exercise in which cardiac vagosympathetic balance tended toward vagus division, corresponding with restoration of total autonomic activity. CONCLUSIONS: An age-related reduction in cardiac autonomic function was consistent with previous reports. The vagosympathetic balance was altered with this reduction: vagal predominance was impaired significantly in proportion to the withdrawal of total cardiac autonomic activity.

Mean systolic ejection rate after aortocoronary bypass graft surgery.

In 62 patients with coronary artery disease who underwent aortocoronary bypass graft surgery, we measured the mean systolic ejection rate invasively at rest and during upright exercise before and several months after operation. After bypass surgery, mean systolic ejection rate did not show any change at either supine or sitting rest and at submaximal exercise levels of walking on a treadmill. At maximal exercise, only patients with complete revascularization showed a significant increase in heart rate from 105 to 147 (+40%) and mean systolic ejection rate from 339 ml/sec to 404 ml/sec (+19%, P less than 0.001). Patients with incomplete revascularization did not show a substantial change in these variables. Beta-blocker withdrawal did not affect the result significantly.

Diabetic alteration of cardiac vago-sympathetic modulation assessed with tone-entropy analysis.

No clear evidence of diabetic alteration of cardiac sympatho-vagal balance has been reported to date. We assessed heart rate variability of diabetic patients with the tone-entropy analysis that has been published elsewhere (Oida et al. 1997). Tone reflects the cardiac vago-sympathetic balance and entropy the total autonomic efferent activity. Diabetic influence on tone and entropy was examined in two groups of patients (38-52 years and 60-69 year, total 106) stratified according to the occurrence of impaired glucose tolerance or diabetes mellitus. Ten healthy middle-aged volunteers were also examined as a reference. Electrocardiographic data were collected at rest for 10 min. Tone increased and entropy decreased significantly with severity of diabetic disorders. The alterations were depicted as a curvi-linear relation in tone-entropy space, which superimposed adequately on the standard tone-entropy values obtained in a pharmacological experiment. The results demonstrate that the vago-sympathetic balance is altered with diabetic disorders: vagal predominance is impaired significantly in proportion to a withdrawal of total autonomic efferent activity.

Augmented mean systolic ejection rate in coronary patients treated with diltiazem.

The effect of a single 120-mg oral dose of diltiazem on the mean systolic ejection rate (MSER) was studied in 18 patients with exercise-induced angina pectoris, at rest, during, and after symptom-limited, multi-stage, treadmill testing. The patients were subdivided into two groups according to the mean pulmonary capillary pressure at maximal exercise. In group I (9 patients), the mean pulmonary capillary pressure was 16 mm Hg or lower, and in group II (9 patients), this variable was higher than 16 mm Hg at maximal exercise. Before diltiazem, MSER increased in response to exercise in both groups. MSER was correlated with stroke volume (r = 0.90), heart rate (r = 0.34), and systemic vascular resistance (r = 0.82), but not correlated with mean pulmonary capillary pressure (r = 0.18) or mean arterial pressure (r = 0.06) for all patients. 1 h after the administration of diltiazem, patients in group I showed no significant change in MSER. Group II patients showed significant increases in MSER at two submaximal workloads (267 vs. 295, p less than 0.05, 292 vs. 325, p less than 0.02), maximal exercise (289 vs. 333, p less than 0.05), and the 3rd min of recovery (216 vs. 278, p less than 0.05). In patients with exertional left ventricular dysfunction, diltiazem improved cardiac performance, and the changes in MSER suggest that contractility was influenced favorably. Increased coronary blood flow is postulated as a mechanism for this improvement.

Long-term study of high-dose diltiazem in chronic stable exertional angina.

The efficacy of a calcium slow channel-blocking drug, diltiazem (360 mg/day), was compared to placebo in 15 men with exertional angina during a 21-week study. Symptom-limited exercise testing was used to evaluate the effects of the drug. Analysis of variance indicated the increase in the values of three time-related variables, time to onset of angina, time to onset of 1 mm ST depression, and total duration of exercise, were highly significant (all p less than 0.001). The increase from the second week of placebo to the last week of diltiazem was 4 X 1 minutes for time to angina, 2 X 4 minutes for time to 1 mm ST depression, and 2 X 3 minutes for total duration. In addition, the differences between mean values of these variables for placebo and corresponding diltiazem period at weeks 3 and 4 were significant (p less than 0.01, p less than 0.01, p less than 0.05) and for diltiazem week 20 and placebo week 21 were significant (p less than 0.005, p less than 0.01, p less than 0.005). Weekly angina frequency was reduced from a mean of 17 episodes/week during placebo to one episode/week during diltiazem (p less than 0.001). Submaximal pressure-rate product was reduced significantly during diltiazem (p less than 0.001), and the ECG evidence of myocardial ischemia was reduced by diltiazem at submaximal (p less than 0.02) and maximal exercise (p less than 0.001). The drug was well tolerated and appears to be effective monotherapy for exertional angina.

Excessive reduction in peripheral resistance during exercise and risk of orthostatic symptoms with sustained-release nitroglycerin and diltiazem treatment of angina.

Acute effects of placebo, sustained-release nitroglycerin, diltiazem capsules, and the combination of both drugs were monitored in nine stable angina patients. They were randomized to receive either placebo or 13 mg of slow-release nitroglycerin orally (double-blind). This was followed in 1 hour by 120 mg of diltiazem orally, given to all patients (unblinded). Invasive hemodynamic measurements were made before and after each treatment at supine and sitting rest, two levels of submaximal, and at maximal exercise and twice in recovery. Compared to the control test at maximal exercise, sustained-release nitroglycerin increased aerobic capacity 24%, lowered peripheral resistance -32%, and lowered systemic pressure -23%, while the respective changes with placebo were -3%, 5%, and 2%. When diltiazem was added to placebo compared to the control test, there was a 4% increase in oxygen consumption and -9% and -4% reduction in systemic resistance and systemic pressure, respectively. The addition of diltiazem to nitroglycerin was associated with a 20% increase in oxygen consumption a -42% reduction in systemic resistance and a -32% reduction in systemic pressure. Two patients who received nitroglycerin plus diltiazem experienced symptomatic hypotension, while one patient who received placebo plus diltiazem experienced hypotension. These side effects caused the study to be terminated prematurely. Thus, although the combination of nitroglycerin and diltiazem had a greater effect on afterload than either drug alone, the combination did not provide greater improvement in cardiac performance.

[Venous flow velocity patterns and cardiac function studied by Doppler echocardiography].

To study the relations of central venous flow velocity (VFV) to cardiac pump function, hepatic venous flow velocity was recorded using Doppler echocardiography in six normal subjects and 47 patients with heart disease, of whom 28 had sinus rhythm and 19, atrial fibrillation. The area under the VFV profile during systole and diastole in a cardiac cycle was computed, and termed the VIs (systolic time-velocity integral) and VId (diastolic time-velocity integral), respectively. VIs was divided by the sum of VIs and VId [VIs/(VIs + VId)], and this was termed the VI ratio. The cardiac index (CI) was estimated by Doppler echocardiography. In normal subjects, the VFV pattern in a cardiac cycle was biphasic, the systolic VFV being dominant. In patients with atrial fibrillation, the systolic VFV was attenuated or absent, the diastolic VFV being dominant. The CI correlated well with the VI ratio (r = 0.80; p less than .001) in 14 patients with atrial fibrillation except for five patients with tricuspid regurgitation. Four patients in whom atrial fibrillation converted spontaneously to sinus rhythm showed an increase in the CI and the VI ratio according to the CI-VI ratio relationship. In patients with sinus rhythm, the CI tended to decrease as the VI ratio increased. In 15 patients who had a VI ratio of over 0.75, the CI correlated inversely with the VI ratio (r = -0.70; p less than 0.01). Three of four patients who had the VI ratio of 1.0 died of congestive heart failure. Although there was positive correlation between the CI and VI ratio in patients without effective atrial contraction, there was inverse correlation in patients with effective atrial contraction. It is suggested that the VI ratio could be a good indicator of cardiac pump function.

[Localized disorders of left ventricular wall motion in congestive cardiomyopathy (author's transl)].

Left ventricular wall motion was studied by two-dimensional echocardiography in 11 patients with congestive cardiomyopathy and was compared with the data of the electrocardiogram and cardiac catheterization. A segmental analysis of left ventricular wall motion was performed using 9 segments obtained by short- and long-axis views of the left ventricle. Left ventricular volume and ejection fraction were calculated from the apical long-axis view by area-length method. Asynergy such as dyskinesis or akinesis was detected in 8 of the 11 patients. Two patients with complete left bundle branch block had asynergy in the septal, anterior and apical segments. In 3 patients with abnormal Q waves inI, aVL and V5,6, asynergy was observed in the different area of the left ventricle in addition to the corresponding region with EKG abnormalities. However, in 3 patients, asynergy occurred without any Q waves. The left ventricle with asynergy had an increased left ventricular end-diastolic volume and left ventricular end-diastolic pressure and a decreased ejection fraction as compared to those without asynergy. As congestive cardiomyopathy had high incidence of asynergy, it was difficult to differentiate congestive cardiomyopathy from ischemic heart disease by two-dimensional echocardiography.

[Echocardiographic findings of variant angina (author's transl)].

Two-dimensional echocardiographic studies of left ventricular wall motion were performed in three patients with ergonovine induced variant angina, who were diagnosed by electrocardiography and/or coronary angiography. The two-dimensional echocardiogram during anginal attack demonstrated hypokinesis or akinesis of the left ventricular wall where ischemia was suspected by the electrocardiogram. This change in the wall motion occurred earlier than that of the electrocardiogram, and the abnormal wall motion in ischemic region returned to normal earlier than the electrocardiographic recovery after the attack. In some cases non-ischemic region showed hypokinesis probably because ergonovine caused coronary artery narrowing in a whole region including spastic region. With relief of the chest pain and restoration of ST segment elevation in the electrocardiogram following nitroglycerin administration, the left ventricular wall tended to be hyperkinetic on the echocardiogram.