Alfred Ioli

Left ventricular shape, afterload and survival in idiopathic dilated cardiomyopathy

Because idiopathic dilated cardiomyopathy is characterized by elevated wall stress and a more spherical left ventricle, the relations among shape, afterload and survival were examined. Thirty-six patients with cardiomyopathy were prospectively studied by two-dimensional echocardiography. Data included echocardiographic short- and long-axis cavity dimensions, their ratio and, with cuff systolic blood pressure, meridional and circumferential end-systolic stress and their ratios. Survivors (n = 16) were followed up for 52 months (range 40 to 76); nonsurvivors (n = 20) died an average of 11 months after study. Survivors had a smaller left ventricular end-diastolic short-axis dimension (6.4 versus 7.1 cm, p less than 0.03) but a similar long-axis length (8.6 versus 8.3 cm). However, overall cavity shape or the ratio of short- to long-axis end-diastolic dimensions was more spherical in those with poorer survival (ratio 0.76 versus 0.68, p less than 0.02). Meridional and circumferential end-systolic stresses were similar in the two groups, but stress was more evenly distributed in the long- and short-axis planes in nonsurvivors (meridional/circumferential stress ratio 0.57 versus 0.52 in survivors, p less than 0.05). Improved survival was associated with an end-diastolic short-axis dimension less than 7.63 cm, a short- to long-axis ratio less than 0.76 and a meridional to circumferential stress ratio less than 0.54. Life table analysis revealed a 28% mortality rate in patients with all three of these characteristics compared with 100% in patients with none. Survivors and nonsurvivors did not differ in systolic cavity dimension, wall thickness, relative wall thickness, cavity volume, percent posterior wall thickening or fractional shortening.(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of afterload, hypertrophy and geometry to left ventricular ejection fraction in aortic valve stenosis, pure aortic regurgitation and idiopathic dilated cardiomyopathy

To investigate the relation of left ventricular (LV) afterload, hypertrophy, geometry and systolic pump function, 17 normal persons, 24 patients with aortic stenosis (AS), 20 with aortic regurgitation (AR) and 15 with idiopathic dilated cardiomyopathy (DC) were studied. Two-dimensional echograms were used to assess end-systolic meridional and circumferential stresses and their ratio, LV mass, relative wall thickness (h/R ratio) and the ratio of LV minor axis to length, used as an index of shape. Independently obtained ejection fraction (EF) was used to determine which patients had normal (EF greater than or equal to 55%) and which had depressed (EF less than 55%) pump function. Patients with AS and low EF had similar LV mass (228 vs 215 g) but larger LV cavity (5.6 vs 4.5 cm), lower h/R ratio (0.53 vs 0.73, p less than 0.01), and therefore higher circumferential stress (336 vs 268 kdyne/cm2, p less than 0.05). Compared with normal persons, patients with DC had a lower h/R ratio (0.28 vs 0.38, p less than 0.01), higher circumferential stress (362 vs 215 kdyne/cm2, p less than 0.01) and more uniform stress distribution (meridional to circumferential stress ratio 0.57 vs 0.39, p less than 0.01), implying that meridional stress overestimates effective afterload. Afterload excess and LV shape change may be important to pump function in patients with AS or DC. In contrast, in those with AR, no significant shape differences were noted, although LV mass was higher in those with low EF (279 vs 211 g, p less than 0.05). Depressed pump function may result from impaired myocardial performance in AR without afterload excess.

Long-term Follow-up of Mitral Paraprosthetic Regurgitation by Transesophageal Echocardiography

Paravalvular regurgitation (PVR) is an uncommon complication of mitral valve replacement (MVR). Although severe PVR is almost always repaired immediately when recognized during surgery, there are little data available on the management of patients with mild and moderate PVR. This study includes eight patients with mild (n = 6) and moderate (n = 2) PVR identified by transesophageal echocardiography at the time of MVR who were treated conservatively. Clinical and echocardiographic follow-up was obtained at a mean of 16.3 months. Two of six patients with mild PVR at the time of MVR and two of two patients with moderate PVR at the time of MVR deteriorated clinically and echocardiographically over time. We suggest that moderate PVR should be corrected at the time of valve-replacement surgery, if this can be performed without high operative risk. Mild PVR should probably also be repaired, if this can be performed at low risk, because some will progress. Patients left with mild PVR after surgery, or patients in whom PVR is recognized only after surgery, should be followed up carefully with serial clinical and echocardiographic examinations.

Role of echocardiography in perioperative management of patients undergoing open heart surgery

TEE has assumed a pivotal role in the perioperative management of patients undergoing open-heart surgery. The information obtained influences important therapeutic decisions in thoracic aortic surgery, valvular surgery, and coronary artery bypass surgery. TEE also assists in determining the reason for failure to wean from cardiopulmonary bypass and allows rapid detection of the etiology of hypotension in the patient after surgery. Advances in technology have resulted in three-dimensional images of cardiac structures, and this will further enhance the usefulness of echocardiography for the surgeon. TEE should no longer be regarded as an imaging tool available only in academic centers, but should be routinely used by qualified operators in centers performing open-heart surgery.

Quantification of mitral regurgitation: a comparison of transesophageal echocardiography and contrast ventriculography.

Transesophageal echocardiography (TEE) allows an unobscured view of the left atrium for the assessment of mitral regurgitation (MR). However, criteria for assessing MR by TEE have not been carefully validated. In order to determine and validate criteria for the assessment of MR severity, 65 clinically stable patients with a TEE color Doppler study and contrast ventriculography within a 2‐week period were identified. Maximal or peak mitral regurgitation jet area to left atrial area ratio (MR/LA) derived solely from TEE imaging had the best correlation to MR severity by contrast ventriculography (r = 0.89). Utilizing MR jet area without correction for LA size resulted in r = 0.72 to 0.75. Utilizing LA area data from transthoracic echocardiograms in a subset of 29 patients resulted in r = 0.77. Best sensitivity and specificity for the assessment of MR by TEE were obtained using the following criteria: Peak MR/LA of 0%‐9% predicts 0+ MR; 10%‐28% 1 + MR; 29%‐54% 2 + to 3 + MR; and >55% 4 + MR. Best sensitivity and specificity occurs for assessment of 0 + and 4 + MR. Considerable overlap in data occurs in the 1 + to 3 + MR range utilizing the above stated criteria. Peak MR/LA ratio derived from a single TEE view in which the MR jet is maximally imaged is the best determinant of MR severity.

Superior Vena Caval Thrombosis Detected by Transesophageal Echocardiography

Three patients with clinical suspicion of bacterial endocarditis, induced by either pacemaker or indwelling catheter, underwent transesophageal echocardiography. High short-axis cuts through the great vessels, however, revealed the presence of superior vena caval thrombus in all three patients. Transesophageal echocardiography is more sensitive in establishing the diagnosis of superior vena caval thrombus than surface echocardiography. Comparison of transesophageal echocardiography with other diagnostic modalities is needed in assessing its overall sensitivity and specificity.

Transesophageal echocardiography in the diagnosis of the persistent left superior vena cava.

Three patients with suspected persistent left superior vena cava (PLSVC) diagnosed by transthoracic echocardiography underwent single-plane transesophageal echocardiography. In all three patients transverse cuts through right atrium and coronary sinus demonstrated the presence of PLSVC. Agitated contrast injection into the left antecubital vein opacified PLSVC and coronary sinus in all cases. Transesophageal echocardiography is superior to transthoracic echo in the diagnosis of PLSVC and associated cardiac anomalies.

Transesophageal Echocardiographic Evaluation of a Transthoracic Echocardiographic Pitfall: A Diaphragmatic Hernia Mimicking a Left Atrial Mass

Diaphragmatic hernia may mimic a left atrial mass when imaged by transthoracic echocardiography. In this case study we emphasize the value of transesophageal echocardiography in clarifying the cause of this apparent atrial mass.

Left Ventricular Outflow Tract Obstruction Following Mitral Valve Replacement with Carpentier‐Edwards Prosthesis

Left ventricular outflow tract (LVOT) obstruction is a rare complication of mitral valve replacement. In this article, we describe three patients in whom left ventricular outflow tract obstruction occurred following Carpentier‐Edwards porcine mitral valve replacement. All three patients presented with symptomatic mitral regurgitation (angiographic grade 3–4) requiring mitral valve replacement. Preoperatively there was no evidence of hypertrophic obstructive cardiomyopathy by physical exam, echocardiography, or by cardiac catheterization. At the time of surgery all three were shown to have severe mitral valve prolapse. The native anterior mitral leaflet was left intact and pledgeted to the mitral annulus. Following surgery a new systolic murmur was appreciated. Echocardiographic exam visualized obstruction of the left ventricular outflow tract by the prosthetic strut in two cases and by a flail anterior leaflet in one case. Continuous‐wave Doppler measured a calculated peak gradient of 72 to 81 mmHg across the left ventricular outflow tract. In one case simultaneous Doppler and cardiac catheterization confirmed the diagnosis and severity of left ventricular outflow tract obstruction. Mechanisms of left ventricular outflow tract obstruction following Carpentier‐Edwards porcine mitral valve replacement are discussed. These three cases highlight the importance of echo‐Doppler techniques in understanding the mechanism of newly detected systolic murmurs following mitral valve replacement.

Variable responses of mitral valve motion and flow in systemic hypertension and in idiopathic dilated cardiomyopathy

The relation between transmitral flow and diastolic mitral valve motion were examined in 17 normal persons, 14 patients with hypertension and 12 patients with idiopathic dilated cardiomyopathy. M-mode echograms were analyzed for early and late diastolic mitral leaflet separations, their ratio and E-F slope. Pulsed Doppler transmitral flow was analyzed for early and late velocities, their ratio and early flow deceleration. Early diastolic mitral valve leaflet separation was reduced in patients with hypertension (at 28 +/- 5 mm [p less than 0.05] ) and in patients with cardiomyopathy (at 22 +/- 3 mm [p less than 0.01] ). Flow velocity was also reduced in patients with hypertension (at 52 +/- 11 cm/s [p less than 0.05] ) and in patients with cardiomyopathy (at 48 +/- 15 cm/s [p less than 0.01] ). However, early leaflet separation and flow velocity were not related (r = 0.26). Late diastolic leaflet separation was similar (at 25 +/- 5 mm) in normal subjects and in those with hypertension (at 23 +/- 6 mm), but was reduced in patients with cardiomyopathy (at 18 +/- 3 mm [p less than 0.01] ). In contrast, late flow velocity was increased in patients with hypertension (at 52 +/- 12 cm/s [p less than 0.05] ) but unchanged in patients with cardiomyopathy (at 42 +/- 16 cm/s). The ratio of early to late leaflet separation was similar in all groups, whereas the ratio of flow velocities was reduced in hypertensive patients. Neither the E-F slope not early flow deceleration was altered in either pathologic group. Thus, hypertension and cardiomyopathy had similar effects in early rather than late diastole.(ABSTRACT TRUNCATED AT 250 WORDS)