Echocardiography in the emergency department.

In the busy emergency department, time-effective and accurate diagnostic and prognostic evaluation is essential Although clinical examination remains the mainstay of appropriate evaluation, remaining diagnostic uncertainty may need to be resolved by use of additional techniques. Echocardiography appears very well suited to the unique environment in the emergency department. It is portable to the patient's bedside, can be performed in minimal time, and results are immediately available. This facilitates correct triage and disposition of complicated cases. Small, hand-carried echocardiography systems have been developed with full imaging and Doppler capabilities. Thus, availability of echocardiography is increasing. Because both image acquisition and interpretation are operator-dependent, realization of full diagnostic potential requires extensive training and post-training experience to maintain proficiency.

ACS, myocardial bridging, Tako-tsubo syndrome and mitral regurgitation.

Isolated systolic compression of the mid portion of the left anterior descending artery (LAD) by a bridge of overlying cardiac muscle is an infrequent but well-recognised angiographic anomaly that is often considered harmless. The long-term prognosis appears to be excellent, but occasional reports of patients with angina pectoris, myocardial infarction and sudden death indicate that this is not always true. The prevalence of the anomaly in the normal population is unknown, but the incidence is low and ischaemic events are rare. Tako-tsubo-like left ventricular dysfunction syndrome (TTS) is characterised by ischaemia, anterior ST-segment elevation, no significant coronary artery disease and reversible ampulla-like left ventricular ballooning in postmenopausal females after emotional or physical stress. Dynamic left ventricular outflow tract (LVOT) obstruction is a rare but potentially fatal complication of acute anterior wall infarction. We present a patient with an acute coronary syndrome (ACS) with ST-segment elevation in the anterior leads, transient TTS and transient LVOT obstruction with systolic anterior motion (SAM) of the mitral valve and severe mitral regurgitation. This is the first report of myocardial bridging associated with TTS, and the first report of TTS associated with dynamic LVOT obstruction with SAM and mitral regurgitation.

Acute and short-term effects of partial left ventriculectomy in dilated cardiomyopathy: assessment by pressure-volume loops.

OBJECTIVES: The aim of this study was to evaluate the short-term effects of partial left ventriculectomy (PLV) on left ventricular (LV) pressure-volume (P-V) loops, wall stress, and the synchrony of LV segmental volume motions in patients with dilated cardiomyopathy. BACKGROUND: Surgical LV volume reduction is under investigation as an alternative for, or bridge to, heart transplantation for patients with end-stage dilated cardiomyopathy. METHODS: We measured P-V loops in eight patients with dilated cardiomyopathy before, during and two to five days after PLV. The conductance catheter technique was used to measure LV volume instantaneously. RESULTS: The PLV reduced end-diastolic volume (EDV) acutely from 141+/-27 to 68+/-16 ml/m2 (p < 0.001) and to 65+/-6 ml/m2 (p < 0.001) at two to five days postoperation (post-op). Cardiac index (CI) increased from 1.5+/-0.5 to 2.6+/-0.6 l/min/m2 (p < 0.002) and was 1.8+/-0.3 l/min/m2 (NS) at two to five days post-op. The LV ejection fraction (EF) increased from 15+/-8% to 35+/-6% (p < 0.001) and to 26+/-3% (p < 0.003) at two to five days post-op. Tau decreased from 54+/-8 to 38+/-6 ms (p < 0.05) and was 38+/-5 ms (NS) at two to five days post-op. Peak wall stress decreased from 254+/-85 to 157+/-49 mm Hg (p < 0.001) and to 184+/-40 mm Hg (p < 0.003) two to five days post-op. The synchrony of LV segmental volume changes increased from 68+/-6% before PLV to 80+/-7% after surgery (p < 0.01) and was 73+/-4% (NS) at two to five days post-op. The LV synchrony index and CI showed a significant (p < 0.0001) correlation. CONCLUSIONS: The acute decrease in LV volume in heart-failure patients following PLV resulted at short-term in unchanged SV, increases in LVEF, and decreases in peak wall stress. The increase in LV synchrony with PLV suggests that the transition to a more uniform LV contraction and relaxation pattern might be a rationale of the working mechanism of PLV.

Impending paradoxical embolus: clinical imaging and successful surgical treatment.

In a patient with pulmonary emboli, transesophageal echocardiography showed a thrombus straddling the foramen ovale (impending paradoxical embolism). Proximal pulmonary emboli were visualized by spiral computed tomography and subsequent surgical treatment, consisting of removal of intracardiac clot, closure of the open foramen ovale and pulmonary embolectomy, was successful.

Radiofrequency catheter ablation of sustained monomorphic ventricular tachycardia in hypertrophic cardiomyopathy.

INTRODUCTION: Incessant monomorphic ventricular tachycardia (VT) with a right bundle branch block morphology and a northwest axis is a rare arrhythmic complication in a patient with hypertrophic cardiomyopathy and apical left ventricular aneurysm. METHODS AND RESULTS: The origin of this VT was localized using the following criteria: the presence of entrainment without fusion, equal intervals from the stimulus to the beginning of the QRS complex and from the electrogram to the QRS complex during VT, and the first postpacing interval identical to the tachycardia cycle length. Radiofrequency energy applied to the septoapical part of the apical left ventricular aneurysm terminated the tachycardia within 2 seconds. CONCLUSION: Using criteria to guide radiofrequency (RF) ablation of VT in patients with coronary artery disease, an incessant monomorphic VT in a patient with hypertrophic cardiomyopathy was successfully ablated.

Pathogenesis of mitral regurgitation in acute myocardial infarction: importance of changes in left ventricular shape and regional function.

The pathogenesis of mitral regurgitation (MR) was determined by quantitative echocardiography in 188 patients with acute myocardial infarction (AMI) within 48 hours after admission. MR was classified, by using color Doppler, as significant (grades 3 to 4) or trivial (grades 0 to 2). Left ventricular (LV) function (global and regional), volume, and shape, as well as mitral valvular features, were measured and analyzed by stepwise logistic regression. Significant MR occurred in 25 (13%) patients. Univariately, recurrent infarction (p < 0.01), LV dilation (p < 0.001) and sphericity (p < 0.001), inferoposterolateral asynergy (p < 0.001), mitral annular dilatation (p < 0.005), and mitral leaflet restriction (p < 0.05) were associated with significant MR. In regression analysis, only recurrent infarction (odds ratio 5.08), LV sphericity index (odds ratio 1.12), and inferoposterolateral asynergy (odds ratio 6.07) were independently associated with significant MR, whereas none of the mitral valvular features examined had an independent association. In conclusion, changes in LV shape and regional function and not mitral valvular changes are prime determinants of significant MR after AMI.

Usefulness of mitral regurgitation in protecting against left ventricular thrombus after acute myocardial infarction.

In conclusion, we documented an increased incidence of LV thrombus in patients with MR after AMI.

Traumatic tricuspid valve rupture with luxation of the heart.

Three patients are described with the combination of a luxation of the heart through a pericardial tear and traumatic rupture of the papillary muscle of the tricuspid valve. In only 1 patient was the dislocation of the heart suspected preoperatively. In all 3 patients operative treatment was performed with considerable delay after the accident; nevertheless, all 3 patients survived. In all cases treatment consisted of repositioning of the heart, closure of the pericardium, and valvular repair of the tricuspid valve.

Doppler left ventricular flow pattern versus conventional predictors of left ventricular thrombus after acute myocardial infarction.

OBJECTIVES: The value of Doppler-derived left ventricular spatial flow patterns in predicting left ventricular thrombus formation after myocardial infarction was compared with that of conventional clinical and echocardiographic variables. BACKGROUND: Assessment of left ventricular thrombosis risk after myocardial infarction is important because of potential embolic sequelae that are reduced by oral anticoagulant agents. METHODS: Clinical, two-dimensional and Doppler echocardiographic data were prospectively obtained in 104 patients with acute myocardial infarction within 48 h of admission. Ventricular flow was assessed by Doppler echocardiography and considered normal when brisk ventricular inflow with simultaneous onset at the mitral valve and apical levels was present, together with alternating directions of apical flow throughout the cardiac cycle. In addition to normal flow, two abnormal flow patterns were recognized: apical rotating flow and vortex ring formation. Oral anticoagulant agents were prescribed only to patients with abnormal flow at admission. The incidence of left ventricular thrombosis was assessed by echocardiography during 9 months of follow-up. RESULTS: Abnormal flow pattern had a positive predictive value of 63% and a negative predictive value of 99%. On stepwise logistic regression analysis, only abnormal flow pattern had an independent relation to left ventricular thrombus (odds ratio 92). CONCLUSIONS: Left ventricular flow pattern derived by Doppler echocardiography soon after admission is superior to conventional clinical and two-dimensional echocardiographic assessment in estimating the risk of left ventricular thrombosis after myocardial infarction.

Left atrial appendage blood flow determined by transesophageal echocardiography in healthy subjects.

Transesophageal echocardiography was performed in 46 healthy subjects to define characteristics of normal left atrial appendage blood flow. Three different flow wave patterns were observed that were heart rate dependent (p < 0.01). A quadriphasic pattern, consisting of 2 diastolic forward (emptying) flow waves each followed by a backward (filling) flow wave, was present in 36 subjects (78%). Triphasic appendage flow was observed in 6 subjects (13%) and biphasic flow in 4 (9%). Mean heart rates among subjects with quadri-, tri- and biphasic flows were 75 +/- 11, 95 +/- 6 and 112 +/- 7 beats/min, respectively. Analysis of pulsed Doppler recordings of subjects with quadriphasic or triphasic appendage flow patterns showed that the onset of transmitral early diastolic peak flow wave was followed at 17 +/- 15 ms by the onset of pulmonary venous diastolic flow and at 43 +/- 17 ms by the onset of the first diastolic forward flow in the appendage. This sequence was constant and independent of heart rate (p < 0.01), suggesting a causal relation between left ventricular relaxation and the first diastolic forward flow wave in the appendage. The second diastolic forward flow followed the P wave on the electrocardiogram at 79 +/- 23 ms. Thus, left atrial appendage blood flow pattern in normal subjects is heart rate dependent, and ventricular relaxation appears to initiate early diastolic emptying of the appendage.

Sudden cardiac death and acute pathology of coronary arteries.

The pathology of sudden cardiac death still is a matter of controversy, particularly with respect to the state of the coronary arteries. A recent study has shown a high incidence of acute lesions and suggests a causal relationship. The present study has been designed to verify whether or not acute coronary arterial lesions occur frequently in patients with sudden cardiac death. Sixteen hearts were available. In each instance the patient had died within 6 hours from the onset of myocardial ischaemia. The coronary arterial system was extensively studied by post-mortem coronary angiography, decalcification, serial blocking and histological sectioning. Acute coronary arterial lesions, defined as plaque fissure, 'isolated' plaque haemorrhage and 'isolated thrombosis', were found in 14 of the 16 hearts (87.5%). The total number of acute lesions in the 14 hearts was 28. In 9 hearts plaque fissures were present, in 7 'isolated' plaque haemorrhages and in 5 an 'isolated thrombus'. Half of all acute lesions had occurred in an atherosclerotic plaque of pre-existing 50-75% luminal narrowing. The present study endorses the concept that acute coronary arterial lesions occur in a high proportion of patients with sudden cardiac death, plaque fissures with intramural haemorrhage and intraluminal thrombosis being the most common abnormality. It is tempting to attribute causal significance to such lesions in patients with sudden cardiac death.