Color M-mode flow propagation velocity and conventional doppler indices in the assessment of diastolic left ventricular function during isometric exercise.

BACKGROUND AND OBJECTIVE: Color M-mode flow propagation velocity (Vp) was shown to be a preload-independent measure of diastolic function. To study the effects of an increase in afterload induced by isometric handgrip exercise on diastolic function assessment in patients with cardiomyopathy, we measured Vp and conventional Doppler indices at baseline and at 30% of predetermined maximum handgrip strength. METHODS: Twenty-four patients with systolic dysfunction were divided into two groups: Group I comprising 12 patients with E/A < 1 (early filling velocity/atrial contraction velocity) and Group II comprising 12 patients with E/A > 1. All the patients underwent measurement of Vp, E velocity, its deceleration time (DT), A velocity, isovolumic relaxation time (IVRT), and pulmonary atrial flow reversal velocity (PFR) at baseline and at 30% of predetermined maximum handgrip strength. Twelve healthy controls underwent these same measurements. RESULTS: When comparing baseline to peak echocardiographic data, no significant changes were noted in Vp in any of the groups while a shift of pulsed Doppler indices of Group I toward a pattern closer to that of Group II was noted and a decrease in E velocity and E/A ratio with an increase in IVRT occurred in healthy controls. CONCLUSIONS: Color M-mode flow propagation velocity seems to be an afterload-independent measure of diastolic function in patients with moderate to severe cardiomyopathy while pulsed Doppler indices are more sensitive to loading conditions induced by isometric exercise.

Unusual evolution of ST elevation acute myocardial infarction.

We report a case of acute ST-segment elevation myocardial infarction with an unusual evolution of ST-segment elevation. Several possible explanations of this progression are discussed with supportive evidence for each explaination. The clinical, electrocardiographic, and angiographic features of this case are also illustrated.

Rapid screening of cardiac patients with a miniaturized hand-held ultrasound imager--comparisons with physical examination and conventional two-dimensional echocardiography.

BACKGROUND: Rapid screening of cardiac patients with a hand-held ultrasound imager (SonoHeart [SH]) could provide valuable clinical information. HYPOTHESIS: Whether the use of this device yields additional information to a carefully conducted physical examination and comparable findings to those of conventional two-dimensional echocardiography (2-D) during inpatient rounds is not well established and is the subject of this study. METHODS: In all, 100 consecutive telemetry patients underwent rapid screening with 2-D and color Doppler SH during inpatient rounds. SonoHeart findings were compared with results from conventional 2-D and physical examination conducted by an attending cardiologist. RESULTS: All patients had interpretable images. Mean scanning time with SH was 5.0 +/- 1.2 min; 2-D and SH findings were comparable. The parameters studied included chamber sizes, left ventricular (LV) systolic function, presence of LV hypertrophy (LVH), wall motion abnormalities (WMA), pericardial effusion (PE), and valvular regurgitations. Mild to moderate valvular regurgitation and LV systolic dysfunction were reliably diagnosed by SH in a number of patients whose symptoms were unrelated to the abnormalities detected. CONCLUSIONS: Rapid screening with SH provides accurate and valuable information that would otherwise be undetected during physical examination. Its introduction into clinical practice may redefine the initial approach to patients with cardiovascular disease.

Real-time three-dimensional echocardiography versus two-dimensional echocardiography in the diagnosis of left ventricular apical thrombi: preliminary findings.

PURPOSE: Real-time 3-dimensional transthoracic echocardiography (RT-3D-TE) with real-time volume rendering (RTVR) offers multiple simultaneous views and spatial definition of intracardiac structures superior to that attainable by 2-dimensional transthoracic echocardiography (2D-TE). We hypothesized that RT-3D-TE would therefore improve identification of left ventricular apical thrombi (LVT). METHODS: Patients were referred to our echocardiography laboratory over an 8-month period. Those diagnosed with a "suspicious" or "definite" LVT on the basis of 2D-TE images underwent RT-3D-TE on the same day. All 2D-TE, RT-3D-TE, and RTVR images were reviewed by 2 independent observers. RT-3D-TE findings were considered positive for LVT if LVT was visualized in both B-scan (apical orthogonal) and C-scan (short axis, with and without tilting angle) planes and on RTVR images, nondiagnostic (or suspicious) for LVT if it was not visualized in all planes, and negative for LVT if it was not visualized in any plane. RESULTS: Thirty patients (19 men and 11 women) with a mean age (+/- standard deviation) of 52 +/- 13 years were enrolled. The interobserver agreement coefficient was 63% for 2D-TE interpretations of LVT and 93% for RT-3D-TE interpretations of LVT (p<0.05). The final interpretations by RT-3D-TE with RTVR were positive for LVT in 16 patients (53%), suspicious for LVT in 4 patients (13%), and negative for LVT in 10 patients (30%). CONCLUSIONS: RT-3D-TE with RTVR offers dramatically clearer echocardiographic findings than does 2D-TE. In particular, RT-3D-TE is able to provide a clear diagnosis of LVT/non-LVT when 2D-TE images are merely suggestive of the disorder. Therefore, RT-3D-TE with RTVR, which is a clinically feasible alternative to 2-dimensional echocardiography, has great potential to positively affect the diagnosis, follow-up, and care of patients with suspected LVT.

Ventricular free wall rupture following acute myocardial infarction.

SUMMARY: Ventricular free wall rupture remains a dreaded complication of acute myocardial infarction. A dramatic fatal presentation is not universal and if recognized early, especially in its sub-acute form, a therapeutic intervention may be lifesaving. Changing trends in its natural history and the previously described pathological subtypes have emerged since the advent of thrombolysis. Although frequently unpredictable, certain clinical, echocardiographic and electrocardiographic signs should suggest the diagnosis. Moreover, knowledge of predisposing risk factors and a high index of suspicion are helpful in early recognition of this complication. In recent years, several different therapeutic approaches have been described including percutaneous seals and surgical mechanical closure of ventricular free wall rupture. In this review, we sought to highlight established and debatable aspects of this pathology to hopefully enhance prompt diagnosis and treatment by all clinicians caring for patients suffering acute myocardial infarction.

Mitral regurgitation following acute myocardial infarction.

Mitral valve regurgitation (MR) is a frequent Doppler echocardiographic finding in patients after acute myocardial infarction (AMI) and an independent predictor of long-term cardiovascular mortality. Reported risk factors include advanced age, prior myocardial infarction, infarct extension, and recurrent ischemia. During the early phase of AMI, transient ischemic MR is common and rarely causes hemodynamic compromise. However, when several chordae tendineae or a papillary muscle ruptures, acute left atrial and ventricular volume overload ensues, leading to abrupt hemodynamic deterioration with cardiogenic shock. Auscultation may be unrevealing due to decreased turbulence. Hence, the importance of a high index of suspicion for acute MR in any patient with acute pulmonary edema in the setting of AMI, especially if left ventricular systolic function is well preserved. Later, ventricular remodeling may lead to MR through annular dilatation or papillary muscle migration with malcoaptation of the leaflets. The widespread availability, ease of use and non-invasive nature of Doppler echocardiography have made it the standard diagnostic tool for detecting MR. Mechanical reperfusion of the infarct-related artery seems to be superior to fibrinolysis in decreasing its incidence acutely and in the long run. Nevertheless, when acute severe MR occurs, unless rapidly diagnosed and treated, this dreaded complication is associated with high morbidity and mortality. Prompt surgical intervention after hemodynamic stabilization is essential to ensure a good short-term and long-term prognosis. This review discusses the incidence, long-term prognosis, associated risk factors, complex pathophysiology, time of occurrence, clinical manifestations, diagnosis, and management of patients with MR after AMI.

Color M-mode flow propagation velocity versus conventional Doppler indices in the assessment of diastolic left ventricular function in patients on chronic hemodialysis.

BACKGROUND AND OBJECTIVE: Color M-mode flow propagation velocity (Vp) has been reported as a preload-independent measure of diastolic function. To study the effects of loading conditions on diastolic function assessment in patients on chronic hemodialysis, we measured Vp and conventional Doppler indices pre- and posthemodialysis. METHODS: Twenty hemodialysis patients with normal systolic function underwent measurement of Vp, early filling velocity (E), its deceleration time (DT), atrial contraction velocity (A), isovolumic relaxation time (IVRT), and pulmonary atrial flow reversal velocity (PFR) pre- and posthemodialysis. Twelve healthy controls underwent these same measurements. RESULTS: Hemodialysis patients had significantly slower Vp at baseline than normal controls, while E/A, DT, IVRT, and pulmonary flow reversal were not significantly different. E, IVRT, and PFR were affected by hemodialysis, while color M-mode flow propagation velocities, A, and DT were not. CONCLUSION: Color M-mode flow propagation velocity seems to be a preload-independent measure of diastolic function in chronic hemodialysis patients in whom isolated diastolic dysfunction appears prevalent.