AIMTo study the effects of hypoxia alone or combined-exercise on blood viscosity and cardiac function of rats.

METHODS22 wistar rats were divided into 3 groups: I normoxic control; II hypoxia and III hypoxia-combined exercise. Rats of II and III groups were subjected to hypobaric hypoxia for 5 weeks (23 h/day). They were first brought to simulated 4 000 m altitude, where rats of the III group were forced to swim for 1 h/day (6 days/week). Then the animals were ascent to 5 000 m. Cardiac function were detected by polygraph, the blood viscosity was assayed by E-viscosimeter, 99mTc radiolabelled frog red blood cell was used to measure the cardiac output.

RESULTSHypoxia alone caused an increase in blood hematocrit (Hct) and viscosity. Cardiac function of the left and right ventricles, especially +/- dp/dt(max) was also increased. Hypoxia-combined-exercise did not cause further increase in Hct, while the blood viscosity was decreased. Cardiac function increased further in both ventricles and the cardiac output was increased by 20% after hypoxia-combined-exercise.

CONCLUSIONDuring acclimatization to hypoxia, moderate exercise can decrease the blood viscosity and increase the cardiac function. These changes may be advantageous in delivering oxygen to tissues and may be favorable for promoting acclimation to high altitude.

Altitude ; Animals ; Blood Pressure ; Blood Viscosity ; Cardiac Output ; Hematocrit ; Hypoxia ; blood ; Rats ; Rats, Wistar ; Swimming ; Ventricular Function, Left ; Ventricular Function, Right

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a kind of inherited cardio-myopathy, which is characterized by fibro-fatty replacement of right ventricular myocardium, leading to ventricular arrhythmia. However, rapid atrial arrhythmias are also common, including atrial fibrillation, atrial flutter and atrial tachycardia. Long term rapid atrial arrhythmia can lead to further deterioration of cardiac function. This case is a 51-year-old male. He was admitted to Department of Cardiology, Peking University Third Hospital with palpitation and fatigue after exercise. Electrocardiogram showed incessant atrial tachycardia. Echocardiography revealed dilation of all his four chambers, especially the right ventricle, with the left ventricular ejection fraction of 40% and the right ventricular hypokinesis. Cardiac magnetic resonance imaging found that the right ventricle was significantly enlarged, and the right ventricular aneurysm had formed; the right ventricular ejection fraction was as low as 8%, and the left ventricular ejection fraction was 35%. The patients met the diagnostic criteria of ARVC, and both left and right ventricles were involved. His physical activities were restricted, and metoprolol, digoxin, spironolactone and ramipril were given. Rivaroxaban was also given because atrial tachycardia could cause left atrial thrombosis and embolism. His atrial tachycardia converted spontaneously to normal sinus rhythm after these treatments. Since the patient had severe right ventricular dysfunction, frequent premature ventricular beats and non-sustained ventricular tachycardia on Holter monitoring, indicating a high risk of sudden death, implantable cardioverter defibrillator (ICD) was implanted. After discharge from hospital, physical activity restriction and the above medicines were continued. As rapid atrial arrhythmia could lead to inappropriate ICD shocks, amiodarone was added to prevent the recurrence of atrial tachycardia, and also control ventricular arrhythmia. After 6 months, echocardiography was repeated and showed that the left ventricle diameter was reduced significantly, and the left ventricular ejection fraction increased to 60%, while the size of right ventricle and right atrium decreased slightly. According to the clinical manifestations and outcomes, he was diagnosed with ARVC associated with arrhythmia induced cardiomyopathy. According to the results of his cardiac magnetic resonance imaging, the patient had left ventricular involvement caused by ARVC, and the persistent atrial tachycardia led to left ventricular systolic dysfunction.
Arrhythmogenic Right Ventricular Dysplasia/complications* ; Atrial Fibrillation ; Humans ; Male ; Middle Aged ; Stroke Volume ; Ventricular Function, Left ; Ventricular Function, Right

The effects of intravenous Verapamil administration on ventricular function were evaluated using grated radionuclide ventriculography in 15 patients with essential hypertension. Verapamil(0.1mg/kg) was injected as a bolus for 2 minutes followed by an infusion of 0.007mg/kg/min. Heart rate, blood pressure, ejection fraction, peak ejection rate, total filling time, and prak filling rate were assessed before and after Verapamil administration. The results were was as follows ; 1) Verapamil administration increased heart rate from 63+/-5 to 75+/-9 beats/min(p<0.01) and reduced systolic and diastolic blood pressure from 156+/-17/99+/-6mmHg to 139+/-16/88+/-6mmHg(p<0.01). 2) Ejection fraction, peak ejection rate, and total filling time were not changed significantly after Verapamil injection. 3) Right and left ventricular peak filling rate increased significantly only in patients in whom it was subnormal in the basal study) from 1.6+/-0.4 to 2.3+/-1.1 end-diastolic volumes/s, p<0.05 and from 2.5+/-0.6 to 3.1+/-0.8 end-diastolic volumes/s, p<0.05, respectively). In conclusion, it was found that intravenous Verapamil administration enhances ventricular diatolic function in patients with essential hypertension.
Blood Pressure ; Heart Rate ; Humans ; Hypertension* ; Radionuclide Ventriculography ; Ventricular Function ; Ventricular Function, Right* ; Verapamil*

No abstract available.
Ventricular Function, Right*

BACKGROUND: Mitral stenosis (MS) and mitral regurgitation (MR) have different pathophysiologies and left ventricular function after miral valve replacement (MVR) in both diseases has been well known. However, there has been no report comparing the change of right ventricular (RV) function immediately after MVR. We evaluated the change of RV function following MVR in MS and MR using a RV ejection fraction (RVEF) thermodilution catheter. METHODS: With IRB approval, 27 patients with MS and 22 patients with MR undergoing MVR were included. Patients with tricuspid regurgitation were excluded. A RVEF catheter was inserted before the induction of anesthesia. Hemodynamic parameters were measured after anesthesia (T1, control), immediately after the termination of cardiopulmonay bypass (T2) and after the sternum was closed (T3). RESULTS: Pulmonary capillary wedge pressure (PCWP) and end systolic and end diastolic RV volume index (RVESVI and RVEDVI) were higher in MS than in MR and there was no difference in RVEF at T1. Heart rate increased and mean pulmonary artery pressure (mPAP), PCWP, and pulmonary vascular resistance significantly decreased at T2 in both groups. RVEF increased and RVESV and RVEDV decreased significantly only in MS after MVR versus that at T2. There was no difference in hemodynamic parameters between both groups at T2 and T3. CONCLUSIONS: RV function was significantly improved in MS but not in MR after MVR. However, there was no significant hemodynamic difference between MS and MR after MVR, though they are known to have different preoperative pathophysilogies and postoperative left heart functions.
Anesthesia ; Catheters ; Ethics Committees, Research ; Heart ; Heart Rate ; Hemodynamics ; Humans ; Mitral Valve Insufficiency ; Mitral Valve Stenosis ; Mitral Valve* ; Pulmonary Artery ; Pulmonary Wedge Pressure ; Sternum ; Thermodilution ; Tricuspid Valve Insufficiency ; Vascular Resistance ; Ventricular Function, Left ; Ventricular Function, Right*

BACKGROUND: Ventricular function is one of the important prognostic factors in patients with coronary artery disease. Among noninvasive approaches for the evaluation of ventricular performance, radionuclide ventriculo-graphy has shown to be of particular values in the patients with myocardial infarction. We have evaluated ven-tricular function with ECG-gated blood pool scan (GBPS) in patients with myocardial infarction of different locations and compared right and left ventricular functions. METHOD: Left and right ventricular function was assessed with multigated blood pool scan in 49 patients at 2-3 weeks after acute myocardial infarction (anterior infarction=23, inferior infarction=19, and lateral infarction=7). Left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), maximal emptying rate, maximal filling rate, phase angle and full width at half maximum (FWHM) of phase angles were measured during rest. RESULTS: 1) LVEF was signifi-cantly lower in the patients with anterior myocardial infarction (32.2%) than that of inferior (46.5%, p<0.001) or lateral infarction (45.5%, p<0.05), but not different between inferior and lateral infarction. 2) RVEF was significantly lower in the patients with inferior myocardial infarction (24.6%) than that of anterior (30.5%, p<0.05) or lateral infarction (36.1%, p<0.001), and RVEF of anterior infarction was significantly lower than that of lateral infarction (p<0.05). 3) Phase angle and FWHM of left ventricle and right ventricle phase histogram were not significantly different among the patients groups with different infarct sites. CONCLUSIONS: Ventricular function was differently affected by different infarct sites. Inferior infarction resulted in a greater reduction in right ventricular ejection fraction. In contrast, LVEF was greatly depressed in anterior infarction than in inferior infarction.
Coronary Artery Disease ; Heart Ventricles ; Humans ; Infarction ; Inferior Wall Myocardial Infarction ; Myocardial Infarction ; Stroke Volume ; Ventricular Function ; Ventricular Function, Left ; Ventricular Function, Right*

Adult ; Echocardiography, Three-Dimensional ; methods ; Heart Ventricles ; diagnostic imaging ; Humans ; Stroke Volume ; physiology ; Ventricular Function ; Ventricular Function, Left ; Ventricular Function, Right

OBJECTIVELeft and right ventricular functions were assessed by cine MR imaging in comparison with echocardiography in healthy volunteers.

METHODSA total of 36 healthy volunteers were examined with breath-hold true FISP cine MR imaging sequence and amended localize methods for left and right ventricular functions. Echocardiography (echo) was also performed in these volunteers.

RESULTS(1) left ventricular global function parameters obtained by MR were as follows: EDV (101.3 +/- 19.2) ml, ESV (42.1 +/- 13.3) ml, SV (69.2 +/- 9.8) ml, EF (59.1 +/- 7.2)%; Right ventricular global function as follows: EDV (118.9 +/- 27.1) ml, ESV (57.6 +/- 16.1) ml, SV (61.2 +/- 12.7) ml, EF (51.9 +/- 4.5)%. (2) EDV measured by MR and echo was similar and ESV measured by MR was significantly higher and the rest parameters were lower than that by echo. There was a good correlation (r = 0.66 - 0.80, P < 0.05) on all parameters obtained by MR and echo.

CONCLUSIONThe present study suggests that cine MR imaging is well applicable to left and right ventricular function and RV volume measurements.

Adult ; Echocardiography ; Female ; Humans ; Magnetic Resonance Imaging, Cine ; Male ; Middle Aged ; Myocardial Contraction ; Ventricular Function, Left ; Ventricular Function, Right

OBJECTIVETo explore the cardiac function of left and right ventricles in children with bronchial asthma at the acute stage and its association with the disease severity.

METHODSThe cardiac function was evaluated by using the American Acuson 128XP/10 Doppler echocardiography in 24 children with acute severe bronchial asthma and 40 children with acute mild bronchial asthma. Thirty-four healthy children were used as normal controls.

RESULTSThe injury of right ventricle diastolic function was predominant in children with mild asthma, and the right ventricle systolic function was also decreased. The systolic and diastolic function of left ventricle remained normal. In children with severe bronchial asthma, the injury of left ventricle systolic function was commonly seen, and the left ventricle diastolic function and the right ventricle systolic and diastolic function were also damaged.

CONCLUSIONSThe cardiac function damage occurs in children with acute bronchial asthma and may be correlated with the disease severity.

Asthma ; physiopathology ; Child ; Child, Preschool ; Echocardiography, Doppler ; Female ; Heart ; physiopathology ; Humans ; Infant ; Male ; Ventricular Function, Left ; Ventricular Function, Right

BACKGROUNDAssessment of the left ventricular (LV) and the right ventricular (RV) volumes and their functions is important for prognostic prediction and clinical decision making. We compared the accuracy for quantifying the LV and the RV volumes in vitro between conventional two-dimensional echocardiography (2DE) and real-time three-dimensional echocardiography (RT3DE).

METHODSThe volumes of 37 rubber-models (10 regularly shaped to simulate normal LV, 7 shaped to simulate LV with symmetric aneurysm, 8 shaped to simulate LV with asymmetric aneurysm, and 12 irregularly shaped to simulate normal RV) and 10 excised canine hearts were measured by RT3DE and 2DE. On RT3DE "full volume" imaging, the inner-surfaces of the rubber-models and canine LV and RV were outlined and the volumes were measured using 2-, 4-, 8- and 16-plane methods with the RT3DE analysis software. On 2DE imaging, the volumes were measured by the Simpson method. The LV and RV volumes measured by drained water were served as reference values, with which we compared RT3DE and 2DE data.

RESULTSIn rubber models mimicking normal LV and LV with symmetric aneurysms, RT3DE results were strongly correlated with reference values (r = 0.795 - 0.998) and there was a good correlation between 2DE estimates and reference values (r = 0.715 - 0.729). There were no significant differences between RT3DE estimates, 2DE results and reference values (P > 0.05). In rubber models mimicking the RV and LV with asymmetric aneurysm, RT3DE strongly correlated with reference values (r = 0.765 - 0.988), but 2DE weakly correlated with reference values (r = 0.518 - 0.592). There were no differences between RT3DE and reference values (P > 0.05), but a significant difference between 2DE and reference values occurred (P < 0.05). For excised canine hearts, there was a strong correlation between RT3DE and reference values (r = 0.728 - 0.914), while 2DE showed a less obvious correlation (r = 0.502 - 0.615). Again, there were no significant differences between RT3DE and reference values (P > 0.05), but there was a significant difference between 2DE and reference values (P < 0.05).

CONCLUSIONSRT3DE can accurately quantify LV and RV volumes and provides a new tool to evaluate LV and RV function. For LV and RV measurements by RT3DE, 8-plane strategy is the optimum choice for accuracy and convenience.

Animals ; Cardiac Volume ; Dogs ; Echocardiography ; Echocardiography, Three-Dimensional ; Heart Ventricles ; diagnostic imaging ; Reference Values ; Ventricular Function, Left ; Ventricular Function, Right