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PubMed1988

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↗
PubMed1992

The failure of radical scavengers to attenuate the incidence of reperfusion arrhythmias despite improvement of cardiac function.

We studied the concomitant effects of scavengers of reactive oxygen species (ROS) on both cardiac function and the incidence of arrhythmias. Isolated rat heart was perfused with a working mode paced at 300 beats/min. The left coronary artery was occluded for 5, 7, 15, or 60 min and reperfused thereafter for 30 min. Superoxide dismutase and catalase were infused from 5 min prior to reperfusion to the end of reperfusion in the scavenger treatment group. In the 60-min ischemia group with scavenger treatment, the cardiac output was significantly higher than that in the untreated group at both 10 and 30 min of reperfusion (P less than 0.01). In the 15-min ischemia group with scavenger treatment, the cardiac output showed a tendency toward a higher value than that in the untreated group. The incidence of reperfusion arrhythmias occurring after a short ischemic time (5, 7, or 15 min) were similar in the scavenger treated and untreated groups; but, with a preceding ischemia of 60 min, the incidence of ventricular tachycardia was higher in the scavenger treated group than in the untreated group (P less than 0.02). In conclusion, scavengers improved contractile dysfunction but did not attenuate the incidence of arrhythmias.

Animals↗
PubMed1978

The effects of arteriovenous shunts on cardiac function in renal dialysis patients--an echocardiographic evaluation.

To estimate the flow rate in arteriovenous dialysis fistulae and its effect on cardiac function we investigated 7 dialysis patients (1 woman, 6 men, mean age 33 +/- 3 years) echocardiographically before and after 10 minutes occlusion of the arteriovenous shunt. Cardiac index was signigicantly raised (4.31 +/- 0.23 l/min/m2) and fell significantly into the normal range to 3.89 +/- 0.11 l/min/m2 after occlusion of the AV fistula. This reduction was mainly due to a fall in heart rate from 82 +/- 4 beats/min to 76 +/- 5 beats/min. The estimated AV fistula flow rate (0.71 +/- 0.17 l/m) has been similarly reported in invasive hemodynamic studies. Parameters of cardiac contractility were in the lower range of normal with an average of 1.16 +/- 0.10 circ/sec for the mean velocity of fiber shortening (Vcf) and 65 +/- 4% for the ejection fraction. These decreased minimally after fistula occlusion. The single echocardiographic measurements of Vcf and ejection fraction showed good correlation (r=0.97) and revealed evidence that only these patients with poor left ventricular function and septal hypertrophy showed improved cardiac performance after occlusion of the arteriovenous fistula. Thus echocardiography may offer the opportunity to select those patients who need small AV-fistulae for optimal renal and cardiac treatment.

Adult↗
PubMed1985

Effects of dopamine, (+/-)-dobutamine and the (+)- and (-)-enantiomers of dobutamine on cardiac function in pithed rats.

The effects of dopamine, (+/-)-dobutamine (racemic mixture) and the (+)- and (-)-enantiomers of dobutamine on myocardial function were evaluated in pithed rats. Dopamine and (+/-)-dobutamine produced effects on cardiac function in pithed rats that were qualitatively similar to those reported for these compounds in humans. The increase in cardiac output produced by dopamine and (+/-)-dobutamine was due mainly to an increase in stroke volume, with increases in heart rate contributing to a significant but lesser degree. For both dopamine and (+/-)-dobutamine, the increase in stroke volume appears to result from an increase in myocardial contractility as assessed by increases in left ventricular (LV) dp/dt. Dopamine produced a marked increase in mean arterial blood pressure, whereas (+/-)-dobutamine only modestly increased blood pressure. The (-)-enantiomer of dobutamine, which possesses mainly alpha-1 adrenoceptor agonist activity, produced dose-dependent increases in cardiac output, stroke volume, LVdp/dt and mean arterial blood pressure, but did not significantly increase heart rate except at high doses. Thus, the increase in cardiac output produced by (-)-dobutamine was derived almost exclusively from an augmentation in stroke volume resulting from an increase in myocardial contractility. In contrast, (+)-dobutamine, which possesses predominantly beta-1 and beta-2 adrenoceptor agonist activity, elicited only a modest increase in cardiac output which was due both to an increase in heart rate and stroke volume. Mean arterial blood pressure was not significantly affected by (+)-dobutamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Cardiac function in endocrine diseases: I. Acromegaly.

The aim of our echocardiographic study was to characterize cardiac function and anatomy of 14 acromegalics (A: 9 women, 5 men; mean age: 42.4 yrs) more closely. The duration of acromegaly in 4 of these patients was between 3 and 12 years; the disease was diagnosed for the first time in the other patients. Double M-mode echocardiography was performed in all patients and the results compared with data obtained from a control group of 24 healthy volunteers (N: 22 men, 2 women; mean age: 23 yrs). The mean left ventricular diameter at end-diastole was greater in the acromegalics than in the controls (A: 55 +/- 6 mm, N: 50 +/- 4 mm; p less than 0.005, means +/- SD). After correction for age and body surface area, it, however, was outside the 95% confidence interval in 5 patients. Left ventricular hypertrophy was present in 3 patients, one of whom had coexistent arterial hypertension. A total of 3 patients were hypertensive. Significantly higher values for the maximal velocity of systolic wall thickening (A: 6.1 +/- 0.6 cm/s, N: 4.2 +/- 0.6 cm/s, p less than 0.001) and diameter change (A: 12.4 +/- 2.0 cm/s, N: 10.6 +/- 1.0 cm/s, p less than 0.005) indicate increased contractility with concurrently increased relaxation; fractional shortening did not differ significantly (A: 38 +/- 5%, N: 37 +/- 5%, ns). The isovolumetric relaxation period at diastole was slightly longer in the acromegalics (A: 70 +/- 17 ms, N: 61 +/- 13 ms, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1988

[Effects of age, weight and heart rate on cardiac function at rest in normal subjects].

The effects of age, body weight, and heart rate on cardiac function and left ventricular (LV) volumes at rest were determined for 203 normal subjects, aged 10 to 75 years, using a multiple linear regression model. LV volume was calculated by the formula: volume = 7 X dimension3/(2.4 + dimension). There were age-related increases in ejection fraction, mean velocity of circumferential shortening (mVcf), fractional shortening (FS), stroke volume (SV), and cardiac output (CO). Weight-related increases in SV and CO were observed. Heart rate-related increases in mVcf and CO were also observed. LV volumes at end-systole and at the end of the rapid filling, and slow filling phases decreased with age and increased with weight. However, end-diastolic volume increased with weight, independently of age. The change in LV volume during the rapid filling phase increased with weight; that during the slow filling phase was independent of age, weight, or heart rate. The change in LV volume during the atrial contraction phase increased with age and weight. The ratio of the change in LV volume during atrial contraction to end-diastolic volume was age-related, but independent of weight and heart rate [(an increase in LV volume during atrial contraction)/(end-diastolic volume) = 0.0032 X age (years) + 0.00042 X weight (Kg) + 0.034 X RR interval (sec)]; (r = 0.67, p less than 0.001). The velocity of change in LV volume during the rapid filling phase decreased and that during atrial contraction increased with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Prospective assessment of cardiac function in patients with Kaposi's sarcoma and the acquired immune deficiency syndrome.

Prospective evaluation of cardiac function was undertaken in 21 patients with Kaposi's sarcoma (KS) and the acquired immune deficiency syndrome (AIDS) as part of a phase II clinical trial of 4'epirubicin. All patients were homosexual or bisexual males of median age 34 years (range 23-65). All patients had disseminated cutaneous involvement by KS and seven had systemic organ involvement. No patient had a history of cardiac symptoms, and physical examination of the cardiovascular system was within normal limits for all patients. The baseline ECG was normal in only nine patients (45%). Five had non-specific S-T segment and T-wave changes. Two had poor R-wave progression, and one patient each had incomplete right bundle branch block, left axis deviation, and voltage criteria suggestive of left ventricular hypertrophy. Radionuclide angiography was performed on all patients and compared to 12 age-matched, low-likelihood male controls. The mean ejection fraction (EF) at rest was 61.0 +/- 8.4%, and was not significantly different from the normal control value of 62.4 +/- 7.0%. Similarly the EF during exercise was 66.7 +/- 5.0%, again not significantly different from the control value of 67.8 +/- 5.8%. A drop in EF during exercise was seen in five of 15 KS patients compared to three of 12 controls. Chamber size was normal for both ventricles in only 14 patients (67%) with right ventricular dilatation seen in seven patients (33%). Wall motion abnormalities were also seen in nine patients (42.9%), with the right ventricle affected in eight patients (38.1%), chiefly involving the apex. No chamber size or wall motion abnormalities were seen in the control patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1992

Cardiac function in obstructive sleep apnea patients following uvulopalatopharyngoplasty.

Obstructive sleep apnea syndrome (OSAS) is associated with severe cardiac arrhythmias and conduction abnormalities. Cor pulmonale and right-sided heart failure may ensue. Uvulopalatopharyngoplasty (UPPP) is one of several treatment modalities suggested for OSAS. Tracheotomy and CPAP treatment in adult OSAS patients and adenotonsillectomy in children with OSAS were shown to lead to improvement in some cardiac parameters. Cardiac function was prospectively evaluated in 19 OSAS patients before and after UPPP. No significant changes after surgery were noted on electrocardiographic studies. Improvement in global and regional function of both ventricles was seen in 91% of the patients. A trend toward significant elevation in left ventricular ejection fraction and a statistically significant increase in right ventricular ejection fraction were observed (45% +/- 9% to 50% +/- 7% [p = 0.007]). Our results support performance of UPPP in selected OSAS patients for relief of potentially life-threatening cardiac pathologies.

Adult↗
PubMedDate not supplied

Cardiac function in the chronically volume-overloaded canine heart.

In the chronically volume-overloaded canine heart due to AV-block evaluations of cardiac function were performed during the development of hypertrophy and at stable hypertrophy. In an early stage (1 and 2 weeks of AV-block) when no or only a slight increase of cardiac muscle occurred, contractility measured from dP/dtmax at comparable load is elevated, while later (10 weeks of AV-block) when stable hypertrophy is present, contractility becomes again normal, In the hypertrophied heart a non-depressed cardiac performance and contractility and functional reserve was established from insitu experiments and from evaluations in the isolated heart.

Animals↗
PubMed1990

Quantitative analysis of cardiac function in non-immunological hydrops fetalis.

The present study was designed to quantitatively evaluate fetal cardiac dysfunction in fetal congestive heart failure associated with cardiogenic hydrops fetalis. Thirty-seven cases of non-immunological hydrops fetalis and/or fetal heart disease were assigned to four groups: (1) hydrops fetalis with structural heart disease; (2) hydrops fetalis without heart disease; (3) structural heart diseases without hydrops, and (4) complete A-V block without hydrops. One hundred and ten control fetuses were also studied. The ejection fraction in the first and third groups was significantly lower than that in the control. In the first group, systolic flow velocity in the descending aorta normalized but gestational age was significantly lower than that in the controls. Compensation of fetal cardiac function in the fourth group (complete A-V block) was noted on the basis of higher flow velocity and higher contractility. The cardiothoracic area ratios of the pathological and control groups were also evaluated.

Female↗
PubMed1990

[Pathophysiological analysis of cardiac function by computer processing of echocardiograms].

Automatic image processing system has been developed for analysis of cardiac function with echocardiograms. Echograms of apical long axis view were transferred to microcomputer system and processed to display three dimensional images of left ventricular myocardium. With this technology, analysis of left ventricular wall thickness in three dimensional manner revealed pathophysiological changes in ischemic heart disease.

Coronary Disease↗
PubMed1977

Dose-dependent depression of cardiac function and metabolism by halothane in swine (Sus scrofa).

Halothane depresses myocardial blood flow and metabolism in the dog, but no studies in man have been published. However, the coronary circulation of the pig is remarkably similar to that of man. The authors investigated the effects of halothane-nitrous oxide anesthesia on cardiac function and metabolism in piglets. Thermodilution cardiac output, catheter-tip-manometer measurement of left ventricular function, electro-magnetic flowmeter measurement of coronary blood flow, and blood and tissue measurements of gases and metabolites were made during 0.04 (control), 0.46 (low concentration), and 1.04 (high concentration) per cent halothane vaporized in nitrous oxide, 60 per cent: oxygen, 40 per cent. Compared with control, the low concentration decreased cardiac output (CO) by 10 per cent, left ventricular systolic pressure (LVSP) by 30 per cent, peak contractile element velocity (Vmax by 34 percent, coronary blood flow (CBF) by 36 per cent, and cardiac oxygen uptake (V02) by 55 per cent. Compared with control, the high concentration decreased CO by 32 per cent, LVSP and Vmax by 53 per cent, CBF by 63 per cent and V02 by 62 per cent. This indicates that the dose-related depression in left ventricular function produced by halothane was accompanied by equivalent decreases in coronary blood flow and oxygen comsumption. There was minimal evidence of anaerobic metabolism in these depressed ventricles. Tissue levels of the high-energy phosplates, adenosinetriphosphate and creatine phosphate, and glycogen were unchanged. It is concluded that changes in cardiac oxygenation and metabolism in the pig during halothane anesthesia result from the changes in ventricular function.

Animals↗
PubMed1987

Influence of diltiazem on cardiac function at organ and molecular level during hypothermic cardiac arrest.

The present study was undertaken to assess the effects of cold crystalloid cardioplegia with and without diltiazem on the functional recovery of the heart, calcium binding and uptake by the sarcoplasmic reticulum, Ca++ATPase of sarcoplasmic reticulum and coronary sinus serum MBCK (MB fraction of creatine kinase) of dogs, after 1.5 h of reperfusion following 1 h of ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass (no ischemic cardiac arrest); group II, cold crystalloid cardioplegia; group III, cold crystalloid cardioplegia with diltiazem. The results showed that the decrease in the index of cardiac contractility and cardiac index which accompanies cold crystalloid cardioplegia is associated with a decrease in the calcium uptake by sarcoplasmic reticulum. The index of myocardial contractility was better preserved with cold crystalloid plus diltiazem than with cold crystalloid alone. This improvement, although partial, in cardiac contractility with cold crystalloid plus diltiazem, was associated with a tendency for an increase towards control values in the calcium uptake by sarcoplasmic reticulum. There were no changes in Ca++ATPase of, and calcium binding by, the sarcoplasmic reticulum of groups II and III when compared to group I. There was a progressive increase in the MBCK of coronary sinus blood in groups II and III. The MBCK of group I was unchanged throughout the experimental protocol. The increases in the MBCK of coronary sinus blood were less in group III than in group II indicating the protective effect of diltiazem on ischemic and reperfusion myocardial injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Effects of terbutaline sulfate on fetal cardiac function.

An isolated heart preparation was used to study the effects of terbutaline sulfate (Brethine) on fetal cardiac function. Pregnant guinea pigs received daily subcutaneous injections of terbutaline for 10 day, whereas a control group received placebo injections. Fetal guinea pig hearts were evaluated for cariodynamic and pathologic differences. Fetuses exposed to terbutaline demonstrated a higher mean heart rate (p less than 0.01), a higher mean heart weight (p less than 0.05), a higher mean heart weight/body weight ratio (p less than 0.01), and a trend toward higher left ventricular systolic pressure levels (p less than 0.1). These hemodynamic responses in fetuses exposed to terbutaline may result in increased functional demands that may predispose myocardial tissue to damage.

Animals↗
PubMed1991

Beneficial effects of yohimbine on posthypoxic recovery of cardiac function and myocardial metabolism in isolated perfused rabbit hearts.

The present study was undertaken to elucidate the possible actions of yohimbine on cardiac function and metabolism in the hypoxic and subsequently reoxygenated myocardium. For this purpose, rabbit hearts were perfused for 20 min under hypoxic conditions, followed by 45 min reoxygenated perfusion, and their functional and metabolic alterations with and without yohimbine treatment were examined. Hypoxia induced cessation of cardiac contractile force, rise in resting tension and depletion of tissue high-energy phosphates, which were poorly recovered by subsequent reoxygenation. Hypoxia also induced release of creatine kinase and ATP metabolites from perfused hearts and increases in tissue calcium and sodium contents, which were further enhanced upon subsequent reoxygenation. When hypoxic hearts were treated with 3 to 30 microM yohimbine, several beneficial effects were observed in a concentration-dependent manner. This included enhancement of posthypoxic recovery of contractile function and suppression of the hypoxia- and reoxygenation-induced rise in resting tension. Hypoxia/reoxygenation-induced release of ATP metabolites was inhibited and restoration of myocardial high-energy phosphates enhanced. Inhibition of reoxygenation-induced rise in tissue calcium and sodium and creatine kinase release were also noted. The findings suggest that suppression of transmembrane flux of ions, substrates and enzymes during hypoxia/reoxygenation plays a role in the posthypoxic functional and metabolic recovery. Yohimbine (3-30 microM) significantly depressed the maximal stimulus frequency the left atria could follow. These results suggest a close relationship between depression in the maximal driving frequency of atria and enhancement of the posthypoxic contractile and metabolic recovery of perfused hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1992

Exercise training improves cardiac function after ischemia in the isolated, working rat heart.

The aim of this study was to determine whether exercise training produces a myocardium intrinsically more tolerant to ischemic-reperfusion injury. Male Fischer 344 rats were treadmill trained for 11-16 wk at one of the following intensities: LOW (20 m/min, 0% grade, 60 min/day), moderate (MOD; 30 m/min, 5% grade, 60 min/day) or intensive (INT; 10 bouts of alternating 2-min runs at 16 and 60 m/min, 5% grade). Cardiac function was evaluated both before and after 25 min of global, zero-flow ischemia in the isolated, working heart model. Compared to hearts from sedentary (SED) rats, postischemic cardiac output (CO) and work were significantly higher in all trained groups. Percent recovery of CO (relative to preischemia) was 36.0 +/- 7.1 in SED and 61.2 +/- 6.5, 68.1 +/- 9.3, and 73.2 +/- 5.0 in LOW, MOD, and INT, respectively. Postischemic increases in stroke volume with increased preload and cardiac work at high work load were significantly higher in INT compared with SED. Coronary flow during initial retrograde reperfusion was significantly enhanced with training and correlated with subsequent recovery of CO (R2 = 0.613). Furthermore, trained hearts had higher phosphocreatine (P less than 0.05) and ATP (P less than 0.01) contents after 45 min reperfusion. It is concluded that exercise training results in an intrinsic myocardial adaptation, allowing greater recovery of cardiac pump function after global ischemia in the isolated rat heart.

Adenosine Triphosphate↗
PubMed1979

Non-invasive assessment of cardiac function in meningitis.

Non-invasive registration of systolic time intervals (STI) and ECG were used in evaluating cardiac function in 12 patients with bacterial and 16 with viral meningitis. On admission, 14 (50%) of the patients had abnormal STI. The preejection period (PEP) was prolonged in 11 patients, while left ventricular ejection time (LVET) was prolonged in two and shortened in four. The PEP/LVET index was increased in eight patients. At discharge PEP was still prolonged in eight patients; seven of these were from the viral meningitis group. LVET increased significantly (p less than 0.02) from the first to the last registration. In the patients with abnormal PEP and PEP/LVET on admission, there was a significant fall (p less than 0.05 and p = 0.02, respectively) to discharge. There was no difference in STI between the patients with viral or bacterial meningitis. Eighteen (64%) of the patients had abnormal STI on one or more registration. ST-T changes in ECG and prolongation of the Q-T interval were found in three patients. Cardiac affection in meningitis seems to occur more often than can be shown by ECG.

Adolescent↗
PubMed1988

Gated radionuclide ventriculography in the evaluation of cardiac function in Duchenne's muscular dystrophy.

Left ventricular ejection fractions were determined in 38 patients with Duchenne's muscular dystrophy. No significant correlation between the severity of respiratory dysfunction or age and cardiac function was seen. We suggest that the cardiac status of each patient should be evaluated separately from his respiratory status, particularly when long-term assisted ventilation is being considered.

Adolescent↗