Pulsed Doppler echocardiography is a noninvasive method with high sensitivity and specificity for the assessment of tricuspid regurgitation. In patients with tricuspid regurgitation, pansystolic unusual Doppler signals are detected in the right atrial cavity, which are interpreted as tricuspid regurgitant flow signals. They distributed in a spindle-shaped area from the tricuspid orifice toward the right atrial posterior wall in parallel with the interatrial septum. The orientation of the range where the regurgitant Doppler signals are detected in the right atrial cavity shows the direction of the regurgitant jet. However, such a result is determined mainly in patients with functional tricuspid regurgitation. In regard to patients with organic tricuspid lesion, different considerations may be necessary. Semiquantitative grading of the severity of regurgitation is possible, based on the distance covered by the regurgitant signals from the tricuspid orifice. Tricuspid regurgitation is demonstrated also by contrast echocardiography. The severity is graded based on the distance reached by regurgitant curvilinear contrast echoes from the tricuspid valve in the M-mode echocardiography. If the ultrasound beam is adequately directed through the tricuspid orifice, the grade estimated by the contrast echoes are well correlated with that by the Doppler. However, if the M-mode is performed without the guide by the two-dimensional image, it may miss the most adequate beam direction for the observation, resulting in underestimating severity. The influences of tricuspid regurgitation are generally seen in the flow pattern of the major veins. However, they are more sharply reflected by the flow condition in the right atrial cavity than by the flows patterns in the major veins.

Blood Flow Velocity↗

PubMedDate not supplied

Effect of pericardium on left ventricular early filling assessed by pulsed Doppler echocardiography.

Pericardial effect on left ventricular early filling was studied in six dogs by use of pulsed Doppler echocardiography. Rapid dextran infusion was used to manipulate left atrial pressure. Left ventricular peak early filling velocities before and after pericardiectomy were measured at different levels of left atrial pressure with right atrial and left ventricular pressures. Peak early filling velocity correlated with mean left atrial pressure before and after pericardiectomy. Before pericardiectomy, when mean right atrial pressure exceeded 12 mm Hg, further increase of the velocity was not observed in spite of volume loading. After pericardiectomy, peak early filling velocity became higher and the slope of the relation line between mean left atrial pressure and the velocity became steeper than before pericardiectomy. When the filling pressure was denoted by the transmural mean left atrial pressure, the points on the relation line before pericardiectomy fell along the relation line after pericardiectomy. We conclude the pericardium exerts an external constraint on left ventricular early filling. Therefore we should not consider the absolute but the transmural filling pressure when estimating left ventricular early diastolic function with use of Doppler-derived left ventricular early filling velocity.

Animals↗

PubMedDate not supplied

Early diagnosis of stuck Starr-Edwards disc valve in mitral position: inconstant and interrupted mitral regurgitation.

The patient was a 40-year-old man with Starr-Edwards disc valve for 21 years without symptoms. Newly developed systolic murmur at the apex was noticed at the monthly medical examination. Doppler color flow mapping indicated severe mitral regurgitation. However, the appearance of mitral regurgitation was not constant. Continuous wave Doppler recording indicated that some of the mitral regurgitations were abruptly terminated at early or mid systole with the disc closing signal. Mitral regurgitation was observed only at bradycardia and on the left lateral position. Cardiac surgery demonstrated no abnormality on the disc valve except small sulci on the rim of the disc. When the disc was tilted in the cage, it was stuck and did not move. Echocardiography was useful in detecting the early stage of stuck artificial valve that might be fatal in the mitral position.

Adult↗

PubMedDate not supplied

Prolonged myocardial contrast echocardiography via peripheral venous administration of QW3600 injection (EchoGen): its efficacy and side effects.

We examined the efficacy and side effects of a newly developed contrast agent for intravenous myocardial contrast echocardiography, QW3600 Injection (EchoGen; Sonus Pharmaceuticals, Bothell, Wash.). Doses of 0.1, 0.2, 0.5, and 0.8 ml/kg of this agent were administered intravenously to 8 open-chested dogs. The left ventricular (LV) myocardium was uniformly well opacified for the 0.5 and 0.8 ml/kg doses, for which the peak intensity was an average of 40 gray levels above the baseline intensity. The myocardial opacification persisted even after the contrast echo intensity in the LV cavity had decreased. After ligation of the coronary artery, the area at risk was clearly delineated by the same doses. The agent emulsion and dissolved bubbles were examined microscopically in vitro and in vivo to elucidate the mechanism of prolonged opacification. A microscopic investigation of the mesenteric vessels of a rat indicated that bubbles had formed, growing as large as 30 to 50 microm [corrected] in diameter. The hemodynamic parameters did not change at low doses (0.1 and 0.2 ml/kg), but the systemic pressure fell and the arterial blood oxygen saturation decreased at high doses (0.5 and 0.8 ml/kg). EchoGen provides prolonged contrast for myocardial contrast echocardiography via peripheral venous administration, although the hemodynamic parameters deteriorate at high doses.

Animals↗

PubMedDate not supplied

Recovery of cardiac function by long-term left ventricular support in patients with end-stage cardiomyopathy.

Effects of long-term left ventricular (LV) support on end-stage cardiomyopathy patients is unclear. We applied our LV assist system (LVAS) to six heart transplant candidates, aged 17 to 49, with dilated cardiomyopathy, including one dilated phase hypertrophied cardiomyopathy. LVAS was installed between the left atrium and the ascending aorta, and the pump was positioned parecorporeally. In all patients, their general condition improved, and their pump flows were kept at 4 to 5 L/min. Exercise was started after stabilization of their general condition under constant pump flow. Natural heart size and function were examined by echocardiography. In the beginning of assist, all patients showed impaired cardiac function and LV dilation. During LV assist, systolic function measured by ejection time improved in all patients. Left ventricular end-diastolic dimension (LVDd), showed a remarkable decrease in two patients, who were weaned from LVAS after 3 months of support. They are doing well more than 1 year and 3 years after removal; peak VO2 levels (ml/min/kg) were 30 at 1.2 years and 27 at 2.7 years after removal. In the other four patients, however, LVDd had no remarkable changes, and three could not be weaned from LVAS. The last was discontinued from LVAS after 5 months of support because of infection and died 2 months after removal. From this experience, long-term LVAS may provide the chance for recovery of the natural heart in patients with end-stage cardiomyopathy. The patients whose hearts showed remodeling were able to be weaned from LVAS, and their heart function maintained in good condition for several years.

Adolescent↗

PubMedDate not supplied

[Diagnosis of coronary artery dehiscence and pseudoaneurysm after modified Bentall operation by Doppler color flow imaging: a case report].

This 48-year-old man presented with anterior chest and back pain in 1981. He was treated with replacement of the ascending aorta and aortic valve under a diagnosis of dissection of the ascending aorta with severe aortic regurgitation. He underwent modified Bentall reoperation for the dilation of the aortic root in 1991. Postoperative two-dimensional echocardiography was performed because of sustained atrial flutter. An echo-free space was detected between the aorta graft and aorta wrapping on the short-axis view. Doppler color flow imaging revealed blood flow from the left coronary artery graft into the echo-free space. This leakage was suspected to be the cause of the echo-free space. Transesophageal echocardiography was performed to conform this hypothesis, which revealed blood flow from the left coronary artery graft into the echo-free space in systole and flow into the left coronary artery graft from the echo-free space in diastole.

Anastomosis, Surgical↗

PubMedDate not supplied

[Timing of inflow to the atrium after ventricular contraction and relaxation: effect of atrial wall stiffness].

A stiff atrium is sensitive to even a small change in its volume, causing a rapid change in the caval vein flow. We hypothesized that the onset of caval vein flow may follow immediately after the onset of a ventricular event in a patient with a stiff atrium. The timing of inflow into the right ventricle and into the atrium were examined by Doppler echocardiography in 20 healthy subjects, 12 patients with constrictive pericarditis, and 10 patients with cardiac tamponade. The onset of diastolic flow in the superior vena cave followed 17 +/- 14 msec after the onset of early diastolic filling flow into the right ventricle in constrictive pericarditis patients, which was significantly shorter than 107 +/- 45 msec in the healthy subjects. The onset of systolic flow occurred 178 +/- 46 msec after the peak of the R wave of the electrocardiogram in cardiac tamponade patients, which was significantly longer than 129 +/- 17 msec in healthy subjects. This time was slightly shorter in constrictive pericarditis (103 +/- 21 msec). We conclude that a short time lag from the onset of a ventricular event to the onset of caval flow indications that the right atrium is stiff.

Adult↗