[Venous return and collapse of the right heart in cardiac tamponade].
To elucidate the characteristics of venous inflow into the heart in cardiac tamponade, transmitral (TMF), transtricuspid (TTF) and superior vena cava (SVC) flows were examined using pulsed Doppler echocardiography in nine mongrel open-chest dogs. Cardiac tamponade was produced by the slow infusion of warmed normal saline into the pericardial sac. With increment of pericardial infusion, right atrial collapse (RAC) developed followed by right ventricular collapse (RVC). The systemic blood pressure became depressed and the left ventricular end-diastolic diameter decreased, even in the RAC state, indicating that RVC is not of the primary significance for cardiac tamponade. Characteristically, peak velocities of TMF and TTF in early diastole decreased concomitantly with RAC and RVC. Neither early diastolic filling time nor its acceleration time was altered during tamponade. These changes in blood flow were accompanied by decrements of transmural filling pressure and abnormal motion of the right ventricle. In SVC flow, the diastolic wave characteristically disappeared. This change seemed to be a reflection of the decrease in peak velocity of early diastolic filling flow into the right ventricle. That is, impairment of cardiac relaxation during cardiac tamponade is represented as decreased filling flow velocity in early diastole.
Beppu
S
S
National Cardiovascular Center, Department of Cardiovascular Dynamics, Suita.
Ikegami
K
K
Izumi
S
S
Nakajima
S
S
Nakatani
S
S
Miyatake
K
K
Nimura
Y
Y
D000818:Animals; D001783:Blood Flow Velocity; D002305:Cardiac Tamponade / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004285:Dogs; D015150:Echocardiography, Doppler; D008943:Mitral Valve / Q000503:physiopathology; D009200:Myocardial Contraction; D014261:Tricuspid Valve / Q000503:physiopathology; D014683:Vena Cava, Superior / Q000503:physiopathology*