Premindra A.N. Chandraratna

Left main coronary arterial patency assessed with cross-sectional echocardiography

Abstract To assess the ability to visualize the left main coronary artery with cross-sectional echocardiography, 123 patients scheduled to undergo coronary arteriography were studied prospectively. The left main coronary artery was visualized with a phased array sector scanner. Coronary arteriography revealed a normal left main coronary artery in 108 of the 123 patients and more than 50 percent stenosis of this vessel in 15 patients. The left main coronary artery was adequately visualized with crosssectional echocardiography in 62 (57 percent) of the 108 patients with an arteriographically normal artery and in 9 (80 percent) of 15 patients with more than 50 percent stenosis of this vessel. Cross-sectional echocardiography indicated a normal left main coronary artery In 59 of the 108 patients with a normal left main vessel on coronary arteriography. In three patients thought to have greater than 50 percent stenosis of the distal left main coronary artery on cross-sectional echocardiography, coronary arteriography revealed significant stenosis of the proximal left anterior descending coronary artery and a normal left main coronary artery. In all nine patients with more than 50 percent stenosis of the left main coronary artery on coronary arteriography and adequate visualization of this vessel on cross-sectional echocardiography, the latter technique revealed narrowing of the lumen of this vessel. It is concluded that: (1) When the left main coronary artery is adequately visualized with crosssectional echocardiography, the presence or absence of more than 50 percent stenosis of this vessel can be assessed. (2) Stenosis of the proximal left anterior descending coronary artery may mimic a distal left main coronary arterial stenosis. (3) Studies on larger numbers of subjects with left main coronary artery disease will help to delineate further the role of cross-sectional echocardiography in evaluating a patient with suspected disease of this artery.

Role of Echocardiography in the Treatment of Cardiac Tamponade

Accumulation of fluid within the pericardial sac results in elevation of intrapericardial pressure with consequent cardiac compression or tamponade. Cardiac tamponade is a life‐threatening condition which requires urgent evacuation of pericardial effusion (PE). Current pericardial evacuation techniques and approaches are varied. Echocardiography provides valuable insights into identifying patients who are suitable candidates and further facilitates pericardiocentesis by improving guidance techniques. Several previous publications have provided excellent reviews of the pathophysiology of cardiac tamponade. We review the clinical presentation and role of echocardiography for diagnosis of tamponade. We focus on medical and surgical approaches for the removal of PE. Moreover, as the clinical and hemodynamic consequences of PE depend on the volume and the rate of accumulation of PE, we review the various scenarios of “small” PE resulting in cardiac tamponade.

Use of contrast echocardiography to detect displacement of the needle during pericardiocentesis.

Bedside pericardiocentesis is a safe and routinely practiced procedure. We report a case in which echocardiography‐guided pericardiocentesis was performed urgently for cardiac tamponade. In this case, there was displacement of the periocardiocentesis needle that was only detected by change in the color of aspirated fluid and confirmed by the use of contrast echocardiography. We proscribe the use of routine echocardiographic monitoring during pericardiocentesis to avoid this type of complication. (Echocardiography 2012;29:E60‐E61)

Noninvasive Visualization of Right Coronary Artery Aneurysms

2 cases of right coronary artery aneurysm visualized with M-mode and cross-sectional echocardiography are described. Echocardiographic visualization of right coronary artery aneurysms is possible when substantial dilation is located proximally.

Detection of Wall Motion Abnormalities during Ambulatory Echocardiography Using a Novel Ultrasound Transducer

Background: This investigation was designed to determine whether transient wall motion abnormalities due to myocardial ischemia induced by walking could be detected by ambulatory echocardiography. Methods: Two groups were studied. Group 1 consisted of 10 males (mean age 34 years) who had no symptoms of angina. Group 2 consisted of eight selected patients (mean 61 years) with angina and angiographic evidence of coronary artery disease. The 2.5 MHz transducer is spherical in its distal part and mounted in an external housing to permit steering in 360°. The external housing was attached to the chest wall using an adhesive patch. The transducer was placed in the 3rd or 4th intercostal space at the left sternal border to permit imaging of the left ventricle (LV) in its short axis and attached to the chest wall. The transducer was interfaced with an Acuson Cypress echocardiography system which was placed on a mobile cart. To permit portability, the echocardiography system was powered by a capacitor (UPS device). The subjects were asked to walk along the corridor as fast as possible for 10 minutes or until the onset of symptoms while pushing the cart. The short axis of the LV was displayed on a monitor and recorded on optical disks. Results: The heart rate, systolic blood pressure (SBP), and double product of Group 1 at rest were 77 ± 3 beats/min, 119 ± 13 mmHg, and 9,150 ± 868, respectively, and increased to 106 ± 8 beats/min, 129 ± 15 mmHg, and 1,3793 ± 2,176 with walking. The baseline heart rate, SBP, and double product were 71 ± 12 beats/min, 130 ± 14 mmHg, and 8,555 ± 1,928 in Group 2 and increased to 94 ± 14 beats/min, 135 ± 20 mmHg, and 12,480 ± 3,830 with walking. All patients in Group 1 had normal wall motion at rest and during walking. Patients in Group 2 had normal wall motion during rest and new wall motion abnormalities were noted in all subjects during walking (anterior septum and/or anterolateral wall in seven, posterolateral wall in one). The wall motion abnormalities resolved shortly after discontinuation of walking. Conclusion: Ambulatory echocardiography permitted the detection of transient wall motion abnormalities in patients with coronary artery disease (CAD). This technique could be potentially useful in evaluating selected patients for myocardial ischemia. (Echocardiography 2012;29:509‐512)

Origin and Site of the Tricuspid Regurgitant Jet Determined by Color Flow Imaging in Ebstein's Anomaly

Fifty patients with tricuspid regurgitation due to a variety of causes including rheumatic heart disease, pulmonary hypertension, atrial septal defect, and tricuspid valve endocarditis (group 1); and seven patients with Ebsteins anomaly of the tricuspid valve (group 2) had color Doppler flow imaging performed. The position of the tricuspid annulus and the site of origin of the turbulent tricuspid regurgitant jet were determined from the apical four‐chamber view. The site of origin of the tricuspid regurgitant jet was at or within 0.5 cm of the level of the tricuspid annulus in all group 1 patients. In contrast, all patients in group 2 had tricuspid regurgitant jets that originated deep in the right ventricle and at a considerable distance from the tricuspid annulus (3.8 ± 1.4 cm, mean ± SD). The distance from the origin of the tricuspid regurgitant jet to the tricuspid annulus was measured and expressed as a ratio to that of the distance from the right ventricular apex to the tricuspid annulus in groups 1 and 2. This ratio was 0.94 ± 0.2 in group 1 and 0.61 ± 0.10 in group 2 patients. In conclusion, the tricuspid regurgitant jet originates at or near the level of the tricuspid annulus except in patients with Ebsteins anomaly. Origin of the tricuspid regurgitant jet distal to tricuspid annulus is a clue to the diagnosis of Ebsteins anomaly and is particularly helpful in those patients in whom the displaced tricuspid leaflet cannot be convincingly demonstrated on the two dimensional echocardiogram.