To define the postnatal changes in ANP secretion in response to mechanical stretch and atrial compliance, experiments have been done in perfused nonbeating rabbit atria with different ages: 1-day, 1-, 2-, 3-, 4-, and 8-wk-old. In 1-day-old-rabbits, an increase in intraatrial pressure resulted in an increase in atrial volume, which was higher than that in 1-wk-old rabbits. Increases in atrial volume stimulated the secretion of ANP with concomitant translocation of extracellular fluid (ECF) into the atrial lumen. However, mechanically stimulated ECF translocation was lower in 1-day-old rabbits than that in 1-wk-old rabbits. Therefore, positive relationship between mechanically stimulated ECF translocation and ANP secretion was shifted upward in 1-day-old rabbits, as compared to 1-wk-old rabbits. Changes in atrial volume and ECF translocation were gradually increased with aging and reached the peak value at 4 wk. The stretch-induced ANP secretion in terms of ECF translocation (the interstitial ANP concentration) was also increased with aging and reached the peak value at 4 wk. The interstitial ANP concentration was dependent on the atrial content of ANP. These data suggest that the higher level of atrial ANP secretion is related to the postnatal changes in atrial volume and unidentified factor.
Aging ; Atrial Natriuretic Factor* ; Atrial Pressure ; Compliance* ; Extracellular Fluid ; Rabbits*

No abstract available.
Angiotensins* ; Atrial Fibrillation* ; Blood Pressure* ; Stroke*

To evaluate the relationship between plasma level of immunoreactive atrial natriaretic factor(IR-ANF) and atrial functional index, we studied 28 cardiac patients undergoing cardiac catheterization.Plasma level of IR-ANF in aorta or pulmonary artery was significantly correlated with mean pulmonary capillary wedge pressure, right atrial mean pressure and pulmonary arterial mean pressure, but not with left artrial dimension. To evaluate the relationship between plasma level of IR-ANF and ventricular function index, we selected 13 patients who had normal artrial pressure and no mitral valular disease among 28 patients.Among ventricular functional indices, only left ventricualr end diastolic pressure was significantly correlated with plasma level of IR-ANF in aorta or pulmonary artery. Other indices, such as cardiac index, ejection fraction and aortic systolic blood pressure were not correlated with plasma level of IR-ANF in aorta or pulmonary artery. We concluded that increase in either left atrial pressure may trigger ANF release in man, although ventricles may not be involved in ANF release significantly.
Aorta ; Atrial Natriuretic Factor* ; Atrial Pressure ; Blood Pressure ; Hemodynamics* ; Humans ; Plasma* ; Pulmonary Artery ; Pulmonary Wedge Pressure ; Ventricular Function

The study consisted of all patients over 35yerars old undergoing surgical repair of atrial septal defect for the period from June 1985, to August 1992. The following results were observed. 1. ASD was closed with patch in 11 (73%) patients. 2. The relationship of pulmonary artery systolic pressure to Qp/Qs ratio was not significant. 3. Before operation 6 patients were in NYHA functional class II. 8 were in class III, After operation 8 patients were in class I, 6 were in class II. 4. Atrial fibrillation has persisted in 3 patients and returned regular rhythm in 1 patient after surgery. 5. There was no operative mortality and we had good surgical results regardless of patient's age.
Adult* ; Atrial Fibrillation ; Blood Pressure ; Heart Septal Defects, Atrial* ; Humans ; Mortality ; Pulmonary Artery

BACKGROUND: Recent development of transesophageal echocardiography(TEE) makes it possible to record pulmonary venous flow velocities(PVFV) accurately. To observe the differences of PVFV between normal controls and patients with severe mitral stenosis and to clarify the effects of percutaneous mitral valvuloplasty(PMV) on PVFV, TEE was performed in 12 normal controls and 11 patients with severe mitral stenosis. METHODS: PVFV was recorded from left upper pulmonary vein in longitudinal view of midesophageal position with a 5 MHz probe. Peak velocity and velocity-time integral(VTI) of systole and diastole were calculated with a digitizer. TEE was performed before and one day after PMV. Hemodynamic data(left atrial pressure, transmitral diastolic pressure gradient and cardiac output) were analyzed to demonstrate the possible correlation with PVFV. RESULTS: 1) 75%(9/12) of normal controls showed 4 distinct phases of PVFV with 2 systolic forward peaks, I diastolic forward and I end-diastolic backward peak. Peak systolic velocity was 52.6+/-.9cm/sec and peak diastolic forward velocity was 36.0+/-10.3cm/sec : Systolic VTI was greater than diastolic VTI, too(11.1+/-3.6cm vs 5.2+/-.6cm). 2) In patients with tight mitral stenosis(mean mitral area : 0.9cm2), most(10/11, 91%) showed one peak of systolic forward flow : Peak systolic velocity(27.8+/-15.8cm/sec) and systolic velocity-time integral(3.4+/-1.8cm)were significantly smaller than those of normal controls, while there was no statistical difference in peak diastolic forward velocity and velocity-time integral(34.5+/-12.7cm/sec, 4.3+/-1.7cm) compared to normal controls. There were no significant differences according to the rhythm. After successful PMV(mean mitral valve area : 1.9cm2) peak systolic and diastolic velocities increased up to 46.9+/-13.8cm/sec, 41.4+/-7.5cm/sec respectively, and systolic increase was statistically significant. The systolic increase of peak pulmonary venous velocity and velocity-time integral was more prominent in normal sinus group compared to patients with atrial fibrillation. 3) In patients with mitral stenosis, there was no correlation between peak diastolic forward velocity of pulmonary vein and peak transmitral early diastolic velocity(r=-0.19, p=0.40) : There was a weak negative correlation between mean left atrial pressure and peak systolic velocity of pulmonary vein(r=-0.46, p=0.03) in the pooled data of pre- and postvalvuloplasty(N=22). Also there noticed a negative correlation between diastolic transmitral pressure gradient and peak diastolic velocity of pulmonary vein(r=-0.49, p=0.02, N=22). CONCLUSION: Pulmonary venous velocities of patients with tight mitral stenosis showed decreased peak systolic velocity and VTI due to increased left atrial pressure and decreased compliance. which normalized immediately after successful PMV. In patients with mitral stenosis there seems to be somewhat different relationships between hemodynamic indices and pulmonary venous flow velocities, and further study with more patients with variable mitral valve area would be necessary to clarify the exact correlation.
Atrial Fibrillation ; Atrial Pressure ; Blood Pressure ; Compliance ; Diastole ; Echocardiography, Transesophageal ; Hemodynamics ; Humans ; Mitral Valve ; Mitral Valve Stenosis* ; Pulmonary Veins ; Systole

PURPOSE: The purpose of this study was to evaluate the hemodynamic effects of external chest compression in state of the heart's beating. METHODS: Ten mongrel dogs were used in this study. Ventricular tachycardia was simulated by using a rapid ventricular pacing and ventricular rate was adjusted and maintained at the rate necessary to achieve a 50-mmHg fall in the baseline systolic aortic pressure. External chest compression was initiated after 4 minutes of simulated ventricular tachycardia and was continued for 4 minutes. Hemodynamic measurements, including the systolic and the diastolic aortic pressure, the right atrial pressure, the carotid blood flow, and the end tidal CO2 tension, were done at baseline, during the simulated ventricular tachycardia (VT), and during the simulated ventricular tachycardia with external chest compression (VT+ECC). RESULTS: The systolic aortic pressure, the diastolic aortic pressure, and the mean right atrial pressure were higher during VT+ECC than during VT (99+/-12 vs 92+/-8 mmHg, p=0.157, 59+/-8 vs 55+/-12 mmHg, p=0.140, and 23+/-8 vs 8+/-2 mmHg, p<0.001, respectively). The carotid blood flow was higher during VT+ECC than during VT (273+/-203 vs 136+/-76 mL/min., p=0.011). The calculated coronary perfusion pressure was lower during VT+ECC than during VT ( 26+/-8 vs 40+/-9 mmHg, p<0.001). The end tidal CO2 tension was not different between VT+ECC and VT. CONCLUSION: In the canine model of simulated ventricular tachycardia, external chest compression had a contradictory hemodynamic effect, including an increase in the cerebral blood flow and a decrease in the coronary perfusion pressure.
Animals ; Arterial Pressure ; Atrial Pressure ; Cardiopulmonary Resuscitation* ; Dogs ; Hemodynamics ; Perfusion* ; Tachycardia, Ventricular* ; Thorax

BACKGROUND AND OBJECTIVES: Tachycardias have various clinical features according to the heart rate, the left ventricular systolic function, the site of origin and the mechanisms of the tachycardias. The primary purpose of this study was to evaluate the role of the origin site and cycle length on the ventricular tachycardia (VT) hemodynamics. Our secondary purpose was to explore the possible hemodynamic differences between the two common supraventricular tachycardias (SVT). MATERIALS AND METHODS: VT was simulated in 18 dogs that had there chests opened by using ventricular pacing (VP) at 3 different sites: the left ventricular apex (LVA), the right ventricular outflow tract (RVOT), and the right ventricular apex (RVA). The mean arterial pressure (MAP), the mean left atrial pressure (MLAP) and the mean pulmonary artery pressure (MPAP) were monitored during VP. To simulate SVT, the right atrial appendage and the right ventricular basal septum were stimulated at different cycle lengths with different ventriculo-atrial (VA) time intervals in another 11 dogs that had their chests opened. The arterial pressure, the pulmonary capillary wedge pressure and the cardiac output was observed during simulated atrial tachycardia (Group I), AVRT (Group II) and AVNRT (Group III). RESULTS: In the VT study, at the same pacing site as of the VP, the MAP was significantly decreased with the VP, and the deltaMAP was significantly increased as the length of the VP cycle shortened. At the same pacing cycle length of the VP, the deltaMAP was significantly greater at the RVA or RVOT than at the LVA. At the same pacing site of the VP, the MLAP and the deltaMLAP were significantly increased as the VP cycle length shortened. In the SVT study, MAP was highest in Group I and it decreased with the decreasing VA interval, but this was not significant. The systolic arterial pressure was significantly higher in Group II than in Group III. The CO was higher in Group I than in the other two groups, with a significant difference, and the CO decreased with shortening of the VA interval, but this was not significant. CONCLUSION: The above results suggest that in addition to the tachycardia rate, the origin site could be an independent factor of the VT hemodynamics. Episodes of AVRT and AVNRT may have a different hemodynamic impact that probably originates from the different timing of the ventricular and atrial contraction.
Animals ; Arterial Pressure ; Atrial Appendage ; Atrial Pressure ; Cardiac Output ; Dogs* ; Heart Rate ; Hemodynamics* ; Pulmonary Artery ; Pulmonary Wedge Pressure ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Supraventricular* ; Tachycardia, Ventricular* ; Thorax

BACKGROUND: To evaluate the left heart function, left atrial pressure(LAP) has been monitored directly via LA catheter and indirectly via Swan-Ganz catheter. But indirect pressure monitor cannot often reflect the LAP precisely. We compared the LAP via LA catheter with central venous pressure(CVP), diastolic pulmonary artery pressure(DPAP) and pulmonary capillary wedge pressure(PCWP) by Swan-Ganz catheter. METHODS: Eleven cardiac-surgical patients whose LAP measurements were needed for clinical management were the subjects of this study. The CVP, DPAP and PCWP by Swan-Ganz catheter, and LAP were measured just after cardiopulmonary bypass, just after sternal closure, after 6 hours and 18 hours from the end of operation. And we divided them into two groups which consisted below 35 mmHg(group I) and over 35 mmHg(group II) of systolic pulmonary artery pressure(SPAP), and compared two groups. RESULTS: In group I, the LAP, CVP, DPAP and PCWP was 11.7+/-3.9 mmHg, 10.5+/-3.9 mmHg, 12.5+/-5.1 mmHg and 12.5+/-4.4 mmHg respectively, and correlation coefficiency of LAP with CVP, DPAP and PCWP was 0.7478, 0.7128 and 0.9002 respectively(p<0.05). In the group II, the LAP, CVP, DPAP and PCWP was 16.5+/-3.2 mmHg, 12.8+/-2.9 mmHg, 23.4+/-3.8 mmHg and 20.8+/-4.7 mmHg respectively and there was no correlation between LAP, CVP, DPAP and PCWP. CONCLUSIONS: The Swan-Ganz catheterization for the estimation of LAP is useful in the patients without pulmonary hypertension, but in the patient with pulmonary hypertension, CVP, DPAP and PCWP do not reflect the LAP.
Atrial Function, Left ; Atrial Pressure* ; Capillaries ; Cardiopulmonary Bypass ; Catheterization, Swan-Ganz ; Catheters ; Central Venous Pressure* ; Heart ; Humans ; Hypertension, Pulmonary ; Pulmonary Artery* ; Pulmonary Wedge Pressure*

BACKGROUND: To evaluate the left heart function, left atrial pressure(LAP) has been monitored directly via LA catheter and indirectly via Swan-Ganz catheter. But indirect pressure monitor cannot often reflect the LAP precisely. We compared the LAP via LA catheter with central venous pressure(CVP), diastolic pulmonary artery pressure(DPAP) and pulmonary capillary wedge pressure(PCWP) by Swan-Ganz catheter. METHODS: Eleven cardiac-surgical patients whose LAP measurements were needed for clinical management were the subjects of this study. The CVP, DPAP and PCWP by Swan-Ganz catheter, and LAP were measured just after cardiopulmonary bypass, just after sternal closure, after 6 hours and 18 hours from the end of operation. And we divided them into two groups which consisted below 35 mmHg(group I) and over 35 mmHg(group II) of systolic pulmonary artery pressure(SPAP), and compared two groups. RESULTS: In group I, the LAP, CVP, DPAP and PCWP was 11.7+/-3.9 mmHg, 10.5+/-3.9 mmHg, 12.5+/-5.1 mmHg and 12.5+/-4.4 mmHg respectively, and correlation coefficiency of LAP with CVP, DPAP and PCWP was 0.7478, 0.7128 and 0.9002 respectively(p<0.05). In the group II, the LAP, CVP, DPAP and PCWP was 16.5+/-3.2 mmHg, 12.8+/-2.9 mmHg, 23.4+/-3.8 mmHg and 20.8+/-4.7 mmHg respectively and there was no correlation between LAP, CVP, DPAP and PCWP. CONCLUSIONS: The Swan-Ganz catheterization for the estimation of LAP is useful in the patients without pulmonary hypertension, but in the patient with pulmonary hypertension, CVP, DPAP and PCWP do not reflect the LAP.
Atrial Function, Left ; Atrial Pressure* ; Capillaries ; Cardiopulmonary Bypass ; Catheterization, Swan-Ganz ; Catheters ; Central Venous Pressure* ; Heart ; Humans ; Hypertension, Pulmonary ; Pulmonary Artery* ; Pulmonary Wedge Pressure*

BACKGROUND: Dynamic echoes in the left atrium, spontaneous echo contrast(SEC), represents a marker for thromboembolic risk in patients(pts) with mitral stenosis(MS). The aims of this study were to determine the factors associated with SEC in pts with MS and to observe the immediate effect of percutaneous mitral, valvuloplasty(PMV) on SEC. METHODS: Biplane transesophageal echocardiography(TEE) including Doppler measurement of left atrial appendage flow was performed before and immediately after PMV in 50 pts with MS[32 in normal sinus rhythm(NSR) and 18 in atrial fibrillation(AF)]. Hemodynamic data of left atrial pressure, transmitral pressure gradient, mitral valve area by Gorlin's method(MVA) and cardiac output(CO) by thermodilution method were obtained before and after successful PMV. RESULTS: Before PMV(MVA of 0.9±0.3cm2), SEC was observed in 60%(30/50) of tight MS (13/32 in NSR, 17/18 in AF). The presence of AF(p=0.001), increased left atrial dimension(p=0.001), decreased appendage peak positive velocity(APPV, p=0.03), decreased MVA(p=0.01) and reduced CO(p=0.001) were positive predictive factors for SEC : AF was the most powerful factor among them. In pts with NSR, MVA(p=0.01) was the only factor for SEC before PMV. After successful PMV(MVA of 2.0±0.4cm2) SEC was still observed in 6 pts(12%) with AF. AF(p=0.001), increased left atrial dimension(p=0.06) and decreased APPV(p=0.001) were favorable factors for persistence of SEC after PMV, but hemodynamic indices were not associated with SEC after PMV. New development of mitral regurgitation after PMV was the only predictive factor for disappearance of SEC(p=0.04). In pts with NSR, PMV promptly normalized the APPV with disappearance of SEC. CONCLUSION: In pts with tight MS, different factors may be associated with SEC according to the rhythm. PMV is an effective method to abolish SEC with hemodynamic improvement. Despite the similar MVA and hemodynamic indices, possible preventive effect of thromboembolism after PMV nay be more prominent in pts with NSR compared to those with AF.
Atrial Appendage ; Atrial Pressure ; Heart Atria ; Hemodynamics ; Methods ; Mitral Valve ; Mitral Valve Insufficiency ; Mitral Valve Stenosis ; Thermodilution ; Thromboembolism