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The effect of fluid resuscitation on cardiac function changes monitored by radionuclide ventriculography in the septic shock baboon model.

Dramatic cardiac volume losses accompanied by a drop in arterial pressure and in pulmonary capillary wedge pressure (PCWP) were found to characterise the baboon model in bacterial septic shock. Loss of vascular tone and a probable vascular fluid leak were regarded as contributing factors. To prove this hypothesis an experiment was planned with the baboon model in septic shock, and an added protocol for fluid administration whereby the pulmonary wedge pressure was kept at 7 +/- 2 mm Hg. The six baboons served as their own controls. Raising PCWP by means of fluid loading resulted in an attenuation of the drop in left ventricular volumes, to a smaller decrease in stroke volume (SV) and smaller increases in left ventricular ejection fraction. The drop in arterial pressure remained and left ventricular stroke work therefore reflected the decrease in SV. Compliance as by EDV/PCWP remained unchanged. Fluid loading therefore, although not normalising the haemodynamic parameters, led to smaller changes and an improvement in some measures of cardiac function.

Animals

[Ultrastructural study of left ventricular myocardium in mitral regurgitation--correlations with postoperative cardiac functions].

Light and electron microscopic examination was carried out in tissue samples which were obtained from the left ventricular free wall in 21 patients with mitral regurgitation during open-heart surgery. Their correlations with postoperative cardiac functions were also studied. The area of the interstitial fibrosis (%fib) was calculated from the light microscopic examination of the tissue samples, and changes of intracellular structures were expressed in scores by means of electron microscopy (EM-SCORE). Postoperative hemodynamics were studied with echocardiography before and after exercise. The hemodynamic parameters consisted of SVI, CI, EF, FS, mVcf and percent changes of these parameters before and after exercise. 1. EM-scores correlated with EF, FS and mVcf at rest with correlation coefficient of -0.653, -0.629 and -0.712 respectively and their significant levels were all less than 0.005. They also correlated with EF, FS and mVcf after exercise with correlation coefficient of -0.665 and -0.708 respectively and their significant levels were all less than 0.005. They also correlated with %delta EF, %delta FS and %delta Vcf with correlation coefficient of -0.79, -0.76 and -0.811 respectively and their significant levels were all less than 0.005. 2. Percent fibrosis did not correlated with the hemodynamics at rest. But they correlated with EF, FS after exercise with correlation coefficient of -0.577 and -0.599 respectively and their significant level reached less than 0.01. They also correlated with %delta EF, %delta FS and %delta mVcf with correlation coefficient of -0.584, -0.599 and -0.571 respectively and their significant levels were all less than 0.01. 3. There were no correlations between EM-score and %fib. 4. There were significant correlations between left ventricular function and myocardial morphology, in patients with mitral regurgitation. The patients with EM-score over 7 and %fib. over 14% showed poor left ventricular function and poor cardiac reserve postoperatively.

Adult

Normal cardiac function with a hybrid heart.

A left ventricular bypass procedure using a cardiac allograft was performed in a patient with a long history of rheumatic heart disease and two aortic valve replacements. Normal cardiac function was reestablished, and the only problem following transplantation was that of serious arrhythmias involving the recipient heart. Eighteen months after left ventricular bypass bacterial endocarditis which was resistant to medical treatment developed on the aortic prosthesis. The patient underwent operation, the prosthesis was removed, and the recipient left ventricle was partially resected and excluded from the circulation. Since then the patient has been asymptomatic and, at the time of writing three years after cardiac allograft, he is our longest survivor.

Arrhythmias, Cardiac

Cardiac function in aneurysmal subarachnoid haemorrhage: a study of electrocardiographic and echocardiographic abnormalities.

Electrocardiographic (ECG) changes are reported frequently after subarachnoid haemorrhage (SAH). The aim of this study was to investigate the functional significance of ECG changes by echocardiographic assessment of cardiac function. Forty-five patients with intracranial aneurysms were studied. All patients had a 12-lead ECG and a two-dimensional echocardiogram. After patients with an history of chronic cardiac disease (n = 4) were excluded, only four patients were found to have wall motion abnormalities. These patients had only minor ECG abnormalities, but severe neurological dysfunction. Conversely, patients with other ECG abnormalities including the deep inverted T waves associated usually with SAH, had normal echocardiograms. We conclude that the ECG is not an accurate predictor of myocardial function after SAH and that myocardial dysfunction is related more closely to severity of neurological condition.

Adolescent

Studies on hemodynamics and cardiac function in the immediate postoperative period following open heart surgery.

Hemodynamics and cardiac function in the immediate postoperative period following open heart surgery were studied by means of a Swan-Ganz catheter and a thermodilution output computer. Pulmonary arterial pressure decreased at 3 hr after operation in congenital and mitral valvular diseases either with or without pulmonary hypertension. Then pulmonary arterial pressure maintained the decreased level subsequently in patients without pulmonary hypertension or with moderate pulmonary hypertension. However, in cases of severe pulmonary hypertension, pulmonary arterial pressure increased concomitantly with the increase of pulmonary arterial resistance in adult cases, but maintained the decreased level in juvenile cases. Pulmonary wedge pressure decreased to 3 hr after operation and maintained the decreased level. Right atrail pressure fluctuated within normal range. The cardiac index and left ventricular stroke work index increased between 3 to 6 hr after operation in congenital and mitral valvular diseases and decreased temporarily between 9 to 30 hr and then increased again. The cardiac index and left ventricular stroke work index in mitral valvular diseases showed values lower than those in congenital heart diseases. The increase of cardiac index and left ventricular stroke work index after open heart surgery was more remarkable in mitral valvular diseases than in congenital heart diseases.

Blood Pressure

Transient responses in cardiac function below, at, and above anaerobic threshold.

Exercise-induced alterations in cardiac function during graded cycling with submaximal and maximal intensities were studied in 13 trained and 13 untrained young men. Stroke volume (SV) and stroke index (SI) at rest and during submaximal and maximal exercise, determined by impedance cardiography, were consistently greater in the trained than in the less fit group. Training-induced bradycardia was evident in the trained group at rest and during submaximal exercise. Even when SV and SI were compared at the same absolute heart rate and left ventricular ejection time, those for the trained group were markedly greater than those for the untrained. SV for the untrained group was relatively diminished above the work rate corresponding to the anaerobic threshold. The difference in SV during exercise may be attributed to inadequate filling due to the smaller stretch of myocardial fibers in diastole and/or lesser systolic emptying of the left ventricle due to the reduced myocardial contractility in systole of untrained individuals.

Adult

[Effect of Polygonum cuspidatum No 4 on the enhancement of cardiac function during burn shock].

A burn shock model was produced in rats by scalding the lumbus and lower extremities with 80 degrees C water for 30 seconds. The variable of cardiac functions were measured with a Cardiac-II-R cardio-output computer. It was shown that heart functions decreased as early as 10 min following scalding. Cardiac output (CO), cardiac index (CI), and stroke volume index (SVI) were reduced by 40% of normal, and stroke work (SW) by 47%. With the decrease of CO, total peripheral resistance (TPR) increased. Two hour later TPR was increased 2.6-fold more than pre-burn level, which made BP maintain nearly normal. TPR started to reduce at 3 hr post-burn, resulting in decrease of BP. The decreased heart function returned to near normal by administration of crystal of Polygonum cuspidatum No 4 (p.c), e.g, CO and CI were increased to 91.0% of pre-burn value, SW to 100.1%, and SVI to 102.0%. The increased TPR was reduced to near normal. Half of p.c.-treated animals survived within 24 hr, but all of simple burn animals and n.s.-treated animals died within 24 hr. Under the condition of no fluid infusion, administration of p.c. could restore the decreased heart function, which showed that besides loss of plasma, direct myocardial depression was one of the reason for the decrease of cardiac output during burn shock. The survival rate of animals with burn shock was enhanced by injection of p.c., which indicated that increasing heart function was a very important measure for the treatment of burn shock.

Animals

The effects of coronary artery disease on cardiac function in nonhypotensive sepsis.

To assess the effects of coronary artery disease on cardiac function in the presence of sepsis, we compared several hemodynamic indices in two groups of septic patients. Group 1 (n = 69) consisted of patients with nonhypotensive sepsis without coronary artery disease. Group 2 (n = 25) comprised septic patients who had clinical evidence of coronary artery disease. All patients were hemodynamically stable and normotensive at the time of the study. None required inotropic support. While the two groups had similar mean heart rates, mean blood pressures, and biventricular filling pressures, the mean cardiac index was significantly lower in group 2 (3.5 +/- 0.9 L/min/m2 vs 4.4 +/- 1.2; p less than 0.05). This lower cardiac index was related to significantly lower end-diastolic volume indices in group #2, not to differences in contractility between groups. Since the ventricular filling pressures of the groups were similar, the differences in end-diastolic volumes indicate differences in the biventricular compliance. In the presence of hyperdynamic, nonhypotensive sepsis, coronary artery disease was associated with a clinically significant impairment of biventricular compliance, which resulted in a reduction in cardiac output and systemic oxygen transport.

Aged

Radionuclide evaluation of cardiac function during sleep in children with bronchopulmonary dysplasia.

The influence of sleep on cardiac function in severe bronchopulmonary dysplasia was assessed in five children 1.5 to 5 years of age. Left and right ventricular ejection fractions (LVEF and RVEF) were investigated by equilibrium radionuclide ventriculography in five children undergoing polygraphic monitoring during the different states of alertness: wakefulness, nonrapid eye movement sleep, and rapid eye movement sleep. Intraobserver and interobserver LVEF and RVEF measurement reproducibility was high. During quiet, supine wakefulness, LVEF was normal, but RVEF was low. During sleep, a decrease in both LVEF and RVEF, expressed as a percentage of the awake value, was marked in the two children with the most nocturnal desaturation and longest duration of paradoxic rib cage motion during inspiration. It is concluded that radionuclide ventriculography can be easily performed during sleep in children and can provide useful information regarding right ventricular function during sleep in children with severe bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia

Cardiac function of WHHL rabbit, an animal model of familial hypercholesterolemia.

To investigate the cardiac function of WHHL rabbit (WHHL), an animal model of familial hypercholesterolemia, electrocardiography (ECG) and echocardiography (UCG) were taken from this species of homozygous type and normolipidemic Japanese White rabbits (controls). In WHHL, two of four had intraventricular conduction disturbances (IVCD) in ECG. UCG study showed that the ejection fraction significantly increased (p less than 0.05) and deceleration time was shortened (p less than 0.01) in WHHL compared to normal controls.

Animals

[Echocardiographic indices of cardiac function and systemic hemodynamics in patients with cardiac fibrillation paroxysms and their dynamics as affected by disopyramide phosphate].

Clinical and echocardiographic studies in 25 chronic coronary patients with atrial fibrillation paroxysms following intravenous administration of 0.61-3.8 mg/kg Rhythmilen or its single oral dose (1.25-2.5 mg/kg), as well as during prolonged treatment with 400-600 mg Rhythmilen daily, demonstrated that their myocardial contractility parameters were reduced in the absence of an attack. Contractility parameters were not basically affected where the drug had no effect. Rhythmilen is an effective anti-arrhythmic agent: it arrests atrial fibrillation paroxysms in 73% and maintains the sinus rhythm when used preventively in 82% of cases.

Disopyramide

Acute hemodynamic effects of indigo carmine in the presence of compromised cardiac function.

This report describes the acute hemodynamic effects of indigo carmine in a surgical patient with compromised cardiac function. A 68-year-old woman with stable but severe cardiac dysfunction and renal artery stenosis was scheduled for an elective aortorenal bypass procedure. No hemodynamic instability occurred during the operation until the patient was administered intravenous (IV) indigo carmine 5 ml. At that time, the patient experienced an acute increase in afterload, which resulted in acute left ventricular failure documented by a decrease in cardiac output (CO) and an increase in pulmonary artery pressure (PAP). Until further studies defining the mechanism for its hypertensive side effect are performed, indigo carmine should be used with caution in patients with severe cardiac dysfunction.

Aged

[Cardiac function noninvasively evaluated by phasic pattern analysis of ventricular power during ejection].

To evaluate cardiac function, ventricular power during ejection (power) and the rate of change of power (dPower/dt) were assessed noninvasively. Power was determined from the product of aortic flow (Fa(t] and brachial arterial pressure (Pa(t]. Fa(t) was measured at the suprasternal notch using an ultrasonic pulsed Doppler flowmeter with a 2 MHz carrier frequency and 10 KHz repetition frequency. The maximum detectable blood velocity was 380 cm/sec. Pa(t) was measured using a newly-developed method based on indirect unloading techniques and an air pressure system. There were 21 normal subjects and seven patients with coronary artery disease in this study. The following results were obtained. There was no significant difference between power patterns calculated by Pa(t) and Pao(t) (aortic pressure measured by catheter). The average peak dPower/dt was 160.2 J/sec2 in normal subjects, 145.2 L/sec2 in patients with ejection fractions greater than 50%, and 93.5 J/sec2 in patients with ejection fraction less than 50%. Peak dPower/dt was significantly decreased in patients with the lower ejection fraction (p less than 0.005). The results indicated that this index is clinically useful in evaluating cardiac contractility.

Adult

Echocardiographic assessment of cardiac function in infants and children.

Echocardiography has become an established technique for the assessment of cardiac function in infants and children. M-mode echocardiography provides measurements of left ventricular diameter and wall thickness and allows calculation of their rate of change during the cardiac cycle. Left and right ventricular systolic time intervals may be determined from recordings of aortic and pulmonary valve motion. Two-dimensional echocardiographic images may be utilized for the determination of left and right ventricular volume and ejection fraction. Compared with other noninvasive imaging methods, echocardiography is a rapid, safe and inexpensive technique. Moreover, future developments are likely to include improved image processing and computer analysis of two-dimensional images.

Cardiac Output

Non-invasive assessment of cardiac function in poisoning with drugs.

Systolic time intervals (STI) have been used in evaluating cardiac function in 21 patients who had taken an overdose of drugs. Registrations were made in all patients on arrival at the hospital and on the third day. On arrival STI was abnormal in 16 patients (76%). At the second registration it was still abnormal in ten (48%). Prolongations of total electromechanical systole (QS2) and preejection period (PEP) were the most frequent findings. The patients with abnormal STI at the first registration showed a significant improvement in QS2 (p less than 0.01) and PEP (p less than 0.05) from the first to the third day. Two of the four patients who had taken amitriptyline in a slow release form showed a prolongation of PEP and an increase in PEP/LVET from the first to the third day, and on patient has a further prolongation of the fifth day. The findings may be explained by a reduction of cardiac contractility caused by the membrane-stabilizing effect of the drugs.

Adolescent

Influence of cardiac function on the diuretic and hemodynamic effects of the loop diuretic piretanide.

The influence of cardiac function on the diuretic and hemodynamic effects of the loop diuretic piretanide was investigated in nine patients with congestive heart failure. The diuretic response to piretanide correlated significantly with the pretreatment cardiac index (r = 0.90). Furthermore, a significant correlation was found between the pretreatment fractional sodium excretion and the cardiac index (r = 0.85). The fractional sodium excretion is reciprocal to the renal sodium and water reabsorption. No change in the hemodynamics was observed prior to the onset of diuresis. At 120 minutes after administration of piretanide, the reduction of mean pulmonary capillary wedge pressure (r = 0.88) and mean right atrial pressure (r = 0.80) was significantly related to the diuretic response. We conclude that the reduced diuretic response to piretanide in patients with low cardiac index is due to increased renal sodium and water reabsorption. The hemodynamic changes following the administration of piretanide are dependent on the diuresis.

Adult

Modified Fontan operation for complex cardiac anomalies--postoperative hemodynamics, cardiac function and clinical status.

The purpose of this paper is to compare and define the postoperative hemodynamics, cardiac function and clinical status after the modified Fontan operation in patients with complex cardiac anomalies. Thirteen consecutive patients (6 with double-outlet right ventricle [DORV] [SLL : 4, SDL : 2], 5 with single ventricle [SV] [A-III : 3, B-III : 1, C-III : 1] and 2 with tricuspid atresia [TA] [Ib : 1, IIb : 1]) underwent the modified Fontan operation. These 13 patients ranging in age from 7 to 42 years of age (mean 18) were catheterized at 7 to 46 months (mean 8 months) postoperatively. Pressure tracings at rest demonstrated a dominant "a" wave in both the right atrium and the pulmonary artery suggesting a marked right atrial contraction after this operation. Left ventricular filling pressure was significantly decreased after the modified Fontan operation in DORV and SV. The ejection fraction and left ventricular end-diastolic volume index were unchanged or slightly increased after the modified Fontan operation. Cardiac index in 6 patients with DORV was significantly increased from rest to exercise by +48% (p less than 0.05) with a significant increase in the stroke volume (p less than 0.05) and with a slight increase in heart rate, but this index in 5 patients with SV and in 2 patients with TA was not significantly increased from rest to exercise. In the postoperative clinical status, 11 of 13 patients were in NYHA class I and 2 in class II at follow-up periods ranging from 4 to 75 months (mean 48 months). These results suggest that the modified Fontan operation can be of value and can provide excellent exercise tolerance for patients with complex cardiac lesions.

Adolescent

Influence of long-term antihypertensive therapy on cardiac function, coronary flow and myocardial oxygen consumption in spontaneously hypertensive rats.

The relationships between cardiac performance, coronary flow, coronary vascular resistance at maximal vasodilatation and myocardial oxygen consumption were determined in isolated hearts from spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY) and from SHR given metoprolol (beta 1-selective blocker) and felodipine (selective calcium antagonist) for 35 weeks. A working heart perfusion system was used. An oxygen electrode allowed continuous measurement of oxygen tension in the venous coronary effluent. Blood pressure was reduced close to normal levels in treated SHR. Treatment also caused a substantial reduction of left ventricular weight. In both treated and untreated SHR, maximal cardiac performance, expressed as peak stroke volume, was enhanced above that of WKY at high perfusion pressures, while performance at low perfusion pressures was clearly reduced in the former groups. At a given workload, myocardial oxygen consumption (mmol O2/min per g) was reduced in both groups of SHR. This suggests a physiological structural adaptation to an elevated cardiac load in hypertension, where more myofibrils contribute to produce a given amount of work and therefore less oxygen is consumed per unit muscle mass. Coronary flow was reduced at any given perfusion pressure and oxygen extraction was increased in untreated SHR versus WKY. By causing regression of hypertensive structural vascular changes, treatment markedly increased coronary flow and correspondingly decreased oxygen extraction. Thus, by enhancing the myocardial nutritional supply with antihypertensive treatment, the reduced cardiac function at low perfusion pressure in untreated SHR was almost normalized.

Animals