Wayne R. Parry

Dilated cardiomyopathy with mitral regurgitation: decreased survival despite a low frequency of left ventricular thrombus.

Ninety-one patients with dilated cardiomyopathy were studied by two-dimensional, pulsed, and color Doppler echocardiography (1) to detect and quantify mitral regurgitation (MR), (2) to record apical flow velocities in systole and diastole, and (3) to detect the presence of left ventricular thrombi. MR was detected in 57% of the patients and thrombi were present in 40%, but the occurrence of both MR and thrombus was rare (8%). Apical flow velocity was significantly higher throughout the cardiac cycle in the group with MR (diastole 15 +/- 7 vs 9 +/- 7 cm/sec; systole 29 +/- 12 vs 16 +/- 13 cm/sec; p less than 0.001 for both), accounting for the rarity of thrombi in this group. Follow-up data on 89% of the patients showed markedly decreased survival in the group with MR (22% vs 60% at 32 +/- 6 months, p less than 0.005), and this was evident even in patients with mild MR. Thus although MR is a noninvasively obtainable marker of a large subgroup of patients with dilated cardiomyopathy protected from left ventricular thrombus formation, it is a sensitive marker of decreased survival.

Flow characteristics in the dilated left ventricle with thrombus: Qualitative and quantitative doppler analysis

In an attempt to determine whether mural thrombus in a dilated left ventricle is associated with specific flow patterns, a study was undertaken to assess qualitatively and quantitatively the flow characteristics by conventional pulsed and two-dimensional Doppler color flow examination. Forty patients with cardiomyopathy formed the study group (20 with an apical thrombus and 20 without). The groups did not differ with respect to age, gender, origin of ventricular dysfunction, ventricular size and ejection fraction. Guided by the Doppler color flow pattern, a quantitative analysis of flow velocity profile in the ventricular inflow and outflow compartments was performed by serial pulsed wave Doppler sampling. Inflow velocity at the ventricular apex was significantly lower in the thrombus group than in the no thrombus group (11.7 +/- 15.3 versus 28.3 +/- 10.5 cm/s, p less than 0.0001). Flow velocities were generally lower in the thrombus group at the other levels in the inflow compartment (that is, mitral anulus, leaflet tips and papillary muscle level). The systolic flow velocity at the apex was similarly significantly lower in the thrombus group than in the no thrombus group (7.1 +/- 8.1 versus 15.3 +/- 7.0 cm/s, p less than 0.001). Additionally, a higher prevalence of mitral regurgitation was noted in the no thrombus group (14 patients) than in the thrombus group (3 patients). Thus, specific abnormal flow profiles are associated with a left ventricular thrombus. Whether the abnormal flow is a primary event in the genesis of left ventricular thrombus or occurs secondary to development of the thrombus cannot be determined from this study.

Flow Patterns in Dilated Cardiomyopathy: A Pulsed-wave and Color Flow Doppler Study

In 48 patients with dilated cardiomyopathy, pulsed-wave and color Doppler examination were performed. In addition, 14 normal patients served as control subjects. Peak inflow velocity at the level of the mitral valve, middle left ventricle, and apex and outflow velocity at the level of the apex, middle left ventricle, and subaortic area were measured. In normal patients there was brisk propagation of inflow velocity to the apex. Patients with dilated cardiomyopathy demonstrated delayed propagation and prolongation of the duration of inflow compared with control subjects (p less than 0.04). Continuous apical flow was visualized in 25% of dilated cardiomyopathies and in no normal patients. Apical velocities were significantly increased in cardiomyopathies with significant mitral regurgitation. Outflow velocities were decreased in dilated cardiomyopathy. In patients with dilated cardiomyopathy and apical dyskinesis, flow directed toward the base was measured in the middle left ventricle during isovolumic relaxation secondary to dyskinetic rebound. Patterns of abnormal flow in dilated cardiomyopathies are readily apparent by color M-mode and two-dimensional color Doppler.

The complementary role of magnetic resonance imaging, Doppler echocardiography, and computed tomography in the diagnosis of dissecting thoracic aneurysms.

Non-ECG gated MRI was compared with 2DE and/or CT scans in 10 patients with dissecting aneurysms proven by angiography and/or surgery. Patient ages ranged from 48 to 85 years (mean 69.6). Six had DeBakey type I dissections and four had DeBakey type III dissections. MRI was diagnostic for aortic dissection in nine cases and suggestive in the tenth. 2DE was diagnostic in six out of nine patients, suggestive in two patients, and nondiagnostic in one patient. CT was diagnostic in the three cases in which it was employed. MRI demonstrated a dilated ascending aorta with thickened walls in all type I dissections as well as an intimal flap and slow flow in the false channel in four patients. In the other two patients with type I dissection, MRI detected the intimal flap in the descending aorta but not in the ascending aorta, whereas 2DE revealed the ascending aortic intimal flap in both of these patients and CT showed it in one of them. In the type III dissections, MRI demonstrated a thickened wall and thrombus in the lumen in all four cases, and the intimal flap in three out of the four. 2DE excluded ascending aortic involvement in all three type III dissections. Six other patients with fusiform dilated ascending aortas had no evidence of dissection by MRI, 2DE, and aortography. Thus, non-ECG gated MRI alone or in combination with 2DE and/or CT is useful in the diagnosis of dissecting thoracic aneurysm and in assessing the extent of the dissection. In addition, the differentiation of dissecting aneurysms of the aorta from fusiform dilatation of the aorta is made possible by these noninvasive techniques.

Peripheral embolization during thrombolytic therapy for left atrial thrombus

Abstract Recent studies have focused attention on the effects of anticoagulants1 and thrombolytic agents in the treatment of left ventricular thrombi.2 We report the use of thrombolytic therapy in a patient with a large left atrial thrombus.

Noninvasive evaluation of mid-left ventricular obstruction by two-dimensional and Doppler echocardiography and color flow Doppler echocardiography

Three patients with midventricular obstruction resulting from three different pathophysiologic mechanisms and differing anatomic bases for the development of obstruction are presented. In the first patient, a membrane-like structure appeared to cause some fixed obstruction, but a superimposed dynamic component to the obstruction was also evident. Papillary muscle hypertrophy with approximation of the papillary muscles during systole was the mechanism in the second patient. In the third patient, apical infarction with hyperdynamic contraction of the mid- and basal portions of the myocardium appeared to be the pathophysiologic mechanism. Color flow Doppler echocardiography was particularly useful in localizing the site of obstruction and allowed further evaluations by pulsed and continuous-wave Doppler techniques to precisely determine pressure gradients.

Acute Consequences and Chronic Complications of Acute Myocardial Infarction

Because preservation of the myocardium is now regarded as one of the key therapeutic strategies in treatment of patients with acute myocardial infarction, i t is essential that all patients be diagnosed promptly upon arrival a t the emergency room or coronary care unit. Although the electrocardiogram clearly has been regarded as the definitive study in deciding which patient should receive immediate thrombolytic therapy and/or percutaneous transluminal coronary angioplasty, two-dimensional echocardiography may provide additional valuable information with regard to regional and global left ventricular function. In some patients presenting with chest pain and nondiagnostic ECGs, such as paced rhythm, conduction disturbances, and left ventricular hypertrophy, two-dimensional echocardiography may provide prompt recognition of regional wall motion abnormalities and acute ischemia. In one study, a group of patients undergoing successful thrombolytic therapy had improvement in regional and global left ventricular function as determined by two-dimensional echocardiography compared to a matched control infarct patient group who did not receive thrombolytic therapy.

The contribution of color Doppler flow imaging to the assessment of a left ventricular thrombus

ing at the end of the programmed V-V interval. Thus, until retrograde conduction fatigues or an external maneuver is performed (e.g., magnet application), “endless” pacing activity exists that is identical to VVI functioning. As in this case, symptoms of the pacemaker syndrome may then be precipitated. Myopotential sensing in the atria1 lead, or a PVC, may serve as the inciting event. With DDD pacemaker operation, PMT has become less frequent due to programmability of the PVARP.4z5 Attention to programming of the PVARP in DDI systems is likewise important. The case reported herein illustrates the variable nature of retrograde conduction through the AV node, with progression over time of VA block. If VA conduction assessed serially by noninvasive means is seen to be changing, appropriate reprogramming of the PVARP may prevent the situation of “endless” VVI-type operation and pacemaker syndrome.

Embolization of a large left ventricular thrombus during two-dimensional and color flow doppler examination in idiopathic dilated cardiomyopathy

Abstract Recent studies indicate that left ventricular (LV) thrombi that protrude and have free intracavitary motion have a high incidence of embolization. 1,2 The reported incidence of embolization for protruding LV thrombi ranges from 41% 1 to 58%, 2 while for highly mobile thrombi the reported incidence varies between 61% 1 and 83%. 2 Two-dimensional echocardiography is a highly sensitive and specific technique for detection of LV thrombi. 3 We report the dislodgement and systemic embolization of a LV thrombus in a patient with dilated cardiomyopathy occurring while undergoing a 2-dimensional echocardiogram examination.