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At least 415 records · Page 23Linked to original sources

Coronary vasospasm inducing dynamic left ventricular outflow tract obstruction.

An 80-year-old man was admitted to the emergency department of our institution due to acute, anterior-wall myocardial infarction and cardiogenic shock. Two-dimensional echocardiography revealed systolic anterior motion of the mitral leaflets with severe left ventricular outflow tract obstruction. Although coronary angiography showed normal coronary arteries, an ergonovine provocation test induced diffuse coronary constriction of the left coronary artery, with chest pain, and ST-T changes seen on the electrocardiogram. These clinical signs caused us to suspect coronary spasm. The present case serves as a reminder that coronary vasospasm may be a factor in the development of dynamic left ventricular outflow tract obstruction. Early detection and intensive efforts to relieve vasospasm, including emergency coronary angiography and intracoronary injection of nitroglycerin, are essential.

Aged↗

Echocardiographic evaluation of left ventricular outflow tract obstruction in complete transposition of the great arteries.

Subpulmonic stenosis in complete d-transposition of the great arteries (d-TGA) is a frequently associated malformation, the precise diagnosis of which is essential for optimal medical and surgical treatment. Sixteen patients with d-TGA and subpulmonic stenosis have been studied by M-mode and two-dimensional (2DE) echocardiography and cardiac catheterization. Dynamic obstruction was found in six patients and fixed stenosis in 10. Systolic anterior motion of the mitral valve without fixed obstruction of the left ventricular outflow tract (LVOT) was present in patients with dynamic stenosis. Measurements of left ventricular end-diastolic posterior wall thickness to minor semiaxis ratio correlated well (p less than 0.001) with the pressure gradient across the LVOT. Various types of anatomic fixed obstruction are described. M-mode echocardiography provides assessment of dynamic obstruction but does not allow quantitative evaluation of the length of the narrowed segment. The latter can be achieved by 2DE, which offers improved definition of different anatomic types.

Adolescent↗

Echocardiographic predictors of left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve after mitral valve reconstruction for myxomatous valve disease.

OBJECTIVE: To determine predictors of systolic anterior motion and left ventricular outflow tract obstruction (SAM/LVOTO) after mitral valve repair (MVRep) in patients with myxomatous mitral valve disease. BACKGROUND: Mechanisms for the development of SAM/LVOTO after MVRep have been described; however, predictors of this complication have not been explored. We hypothesize that pre-MVRep transesophageal echocardiography (TEE) can predict postrepair SAM/ LVOTO. METHODS: Using TEE, the lengths of the coapted anterior (AL) and posterior (PL) leaflets and the distance from the coaptation point to the septum (C-Sept) were measured before and after MVRep in 33 patients, including 11 who developed SAM/LVOTO (Group 1) and 22 who did not (Group 2). RESULTS: Group 1 patients had smaller AL/PL ratios (0.99 vs. 1.95, p < 0.0001) and C-Sept distances (2.53 vs. 3.01 cm, p = 0.012) prior to MVRep than those in Group 2. Resolution of SAM/LVOTO was associated with increases in AL/PL ratio and C-Sept distance. This reflects a more anterior position of the coaptation point in those who developed SAM/ LVOTO. CONCLUSIONS: These data suggest that TEE analysis of the mitral apparatus can identify patients likely to develop SAM/LVOTO after MVRep for myxomatous valve disease. The findings are consistent with the concept that SAM of mitral leaflets is due to anterior malposition of slack mitral leaflet portions into the LVOT. The position of the coaptation point of the mitral leaflets is dynamic and a potential target and end point for surgical designs to prevent SAM/LVOTO post MVRep.

Aged↗

The midterm and long-term results of the Mustard operation in patients with transposition of the great vessels and dynamic left ventricular outflow tract obstruction.

Eight of 43 patients with transposition of the great vessels (TGV) and either an intact ventricular septum or very small ventricular septal defect were found to have dynamic left ventricular outflow tract obstruction (LVOTO). The preoperative left ventricle-pulmonary artery (LV-PA) pressure gradient ranged between 14 and 60 mm Hg. In 3 patients the pulmonary artery could not be catheterized. They had a left ventricular pressure of 43, 45, and 62 mm Hg, respectively, no evidence of pulmonary vascular disease, and either echocardiographic or angiocardiographic demonstration of LVOTO. The outflow tract was explored in 3 patients at the time of the Mustard operation. Exposure of the LVOT was difficult, particularly in patients less than 6 months of age. A shallow septal myectomy was performed in 1 patient; a thin fibrous endocardial scar was resected in 2; and no procedure was performed in the third. All 8 patients survived and remain asymptomatic 1 to 11 years (mean, 5 years) after operation. The LV-PA pressure gradient has either remained the same or has increased in every patient except 1 in whom there was a slight reduction in the gradient. We conclude that dynamic LVOTO persists after the Mustard operation and is not amenable to direct surgical relief. However, an excellent clinical result can be obtained for up to 11 years after operation.

Child, Preschool↗

Dynamic left ventricular outflow tract obstruction: an unusual mechanism mimicking anterior myocardial infarction with cardiogenic shock.

Cardiogenic shock is a frequent and threatening complication in the course of acute myocardial infarction. Besides the well known causes (left ventricular failure, acquired interventricular defect, papillary muscle rupture, free wall rupture) other less frequent mechanisms recognize a functional substrate. The recognition of such mechanisms makes us to revert to the treatments with completely different prognostic implications. In our Coronary Care Unit we encountered, in a period of 12 months, 4 patients who presented clinical, electrocardiographic and/or echographic signs and symptoms of acute myocardial infarction, with different degrees of heart failure up to cardiogenic shock. Only 1 patient showed a severe stenosis of the left anterior descending coronary artery and a significant creatine kinase reduction. Left ventriculography, performed at admission, was unable to disclose the true mechanism of clinical presentation. Only a thorough echographic examination disclosed the presence of a dynamic left ventricular outflow tract obstruction as the cause of heart failure culminating in cardiogenic shock. Once recognized, pathophysiological treatment (administration of beta-blockers and withdrawal of vasodilators, inotropic drugs and intra-aortic balloon pump) led to a dramatic improvement, with an almost complete left ventricular function recovery. Left ventricular outflow tract obstruction is a mechanism that can lead to severe heart failure as a complication of an acute myocardial infarction. Conversely such a mechanism can be precipitated by other causes (hypotension, hypovolemia, especially in hypertensive patients) and can mimic an acute myocardial infarction. Its incidence is not negligible: in our Coronary Care Unit it accounted for about 15% of all cases of myocardial infarction requiring inotropic support. An accurate echocardiographic examination is mandatory even after coronary angiography, and always permits the physician to select the appropriate therapy.

Adrenergic beta-Antagonists↗

Dynamic left ventricular outflow tract obstruction in critically ill patients: role of transesophageal echocardiography in therapeutic decision making.

A paradoxic hypotensive response to resuscitative treatment may be the first clue to dynamic left ventricular outflow tract obstruction (DLVOTO) in critically ill patients. If unrecognized, routine interventions aimed at improving cardiac performance may actually result in hypotension and low cardiac output, thus putting patients at risk for adverse event. It is imperative, therefore, that the pathophysiologic processes involved in DLVOTO be fully understood in order to initiate safe and appropriate therapy in critically ill patients. Our presentation and discussion focus on a hypotensive critically ill patient with unrecognized DLVOTO until further evaluation with transesophageal echocardiogram (TEE). We recommend that early TEE be performed on critically ill patients with unexplained hypotension that is poorly responsive to conventional resuscitative measures.

Adrenergic alpha-Agonists↗

Late development of left ventricular outflow tract obstruction after repair of double-outlet right ventricle.

A 22-year-old woman had exertional chest pain and dyspnea secondary to left ventricular outflow tract obstruction more than a decade after repair of a type I double-outlet right ventricle. The obstruction was the result of (1) failure of the ventricular septal defect and the tunnel created between the left ventricle and aorta to enlarge commensurate with growth of the heart and (2) a markedly hypertrophied parietal band of the crista supraventricularis which surrounded and narrowed the aortic orifice. At reoperation, the ventricular septal defect and the tunnel were enlarged and the hypertrophied crista supraventricularis was partially resected. The patient is asymptomatic 6 months after operation.

Adolescent↗

Effects of dual-chamber pacing in hypertrophic cardiomyopathy on left ventricular outflow tract obstruction and on diastolic function.

Hypertrophic cardiomyopathy (HC) is characterized by impaired diastolic function and, in about 1/4 of patients, left ventricular (LV) outflow tract obstruction. Atrioventricular (AV) pacing diminishes LV outflow tract gradient in HC, but impairs diastolic function in the experimental animal and in different categories of patients. To investigate the effects of AV pacing on hemodynamics and LV function in obstructive HC, 16 patients with HC were studied by cardiac catheterization and simultaneous radionuclide angiography during atrial and AV pacing. The resting LV outflow tract gradient decreased with AV pacing from 60 +/- 34 to 38 +/- 37 mm Hg (mean +/- SD; p <0.001). Regional ejection fraction decreased significantly at the septal level from 0.81 +/- 0.21% to 0.69 +/- 0.27% (p <0.01). Pulmonary artery wedge pressure increased from 10 +/- 5 to 15 +/- 6 mm Hg (p <0.001). AV pacing induced asynchrony (i.e., the coefficient of variation of the time to end-systole increased from 7 +/- 4% to 14 +/- 10% (p <0.01). The time constant of isovolumetric relaxation (t) increased from 58 +/- 24 to 74 +/- 33 ms (p <0.02), and peak filling rate decreased from 491 +/- 221 to 416 +/- 184 ml/s (p <0.05). Thus, AV pacing greatly diminishes resting obstruction through a reduction in septal ejection fraction (i.e., an increase in LV outflow tract width in systole), but impairs active diastolic function and increases filling pressures. These latter effects are potentially detrimental in patients with HC in whom diastolic dysfunction is present.

Adult↗

Echocardiographic insights into the mechanisms of relief of left ventricular outflow tract obstruction after nonsurgical septal reduction therapy in patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVES: We sought to evaluate the mechanisms by which nonsurgical septal reduction therapy (NSRT) reduces left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) both acutely and on a long-term basis. BACKGROUND: NSRT reduces LVOT obstruction in patients with HOCM and leads to symptomatic improvement. The mechanisms involved, however, are not well studied. METHODS: An initial group of 30 HOCM patients (age 46 +/- 17, 16 women) who underwent NSRT had echocardiographic studies performed at baseline and six months after the procedure. Measurements included LVOT diameter, end-diastolic distance between the anterior mitral leaflet and interventricular septum, septal base function and the angle between LV systolic flow and the protruding mitral leaflets. In addition, pulse Doppler recordings at a point 2.5 cm apical to the mitral valve were acquired and analyzed for peak and mean ejection velocity, peak acceleration rate and the ratio of acceleration time to ejection time (AT/ET). RESULTS: Significant changes were observed after the procedure, with widening in the LVOT, thinning and akinesis of the septal base, decrease in the angle between LV systolic flow and the protruding mitral leaflets, a decrease in peak acceleration rate and an increase in AT/ET. All of these variables had significant relations with the decrease in LVOT obstruction (r = 0.5 to 0.79, p < 0.01). These correlations were then evaluated in a test group of 15 patients who underwent echocardiographic examinations at baseline, acutely in the catheterization laboratory with ethanol injection and at six weeks post NSRT. Acute changes in peak acceleration rate (r = 0.65) and AT/ET (r = 0.73) related significantly (p < 0.01) to the decrease in LVOT obstruction with ethanol. At six weeks, changes similar to those noted in the initial group were observed in LVOT geometry, the angle between LV systolic flow and the protruding mitral leaflets, peak acceleration rate and AT/ET. In both populations combined, these parameters accounted for 72% to 77% of the variance in gradient reduction. CONCLUSIONS: Changes in LV ejection dynamics and septal base function account in part for the acute relief of LVOT gradient after NSRT. The long-term relief of obstruction is dependent on remodeling of LVOT as well as the changes in LV ejection.

Adult↗

Left ventricular outflow tract obstruction: an indication for intraoperative transesophageal echocardiography.

Transesophageal echocardiography (TEE) provides detailed anatomic imaging of both discrete and complex forms of left ventricular outflow tract (LVOT) obstruction, and Doppler techniques provide additional information regarding the site, mechanism, and severity of the obstruction. Because the transaortic surgical approach to LVOT obstruction often provides limited direct visualization during surgery, we sought to evaluate the utility of intraoperative TEE during surgery for LVOT obstruction. We tested the hypotheses that intraoperative TEE would (1) be useful in defining the level and nature of LVOT obstruction, (2) serve to direct the surgical approach, (3) define the adequacy of relief of LVOT obstruction, and (4) detect surgical complications. Study population consisted of a consecutive series of 27 infants and children undergoing surgery for LVOT obstruction. Patient age ranged from 0.5 to 17.9 years, and weight from 5.4 to 71.2 kg. In 14 patients LVOT obstruction resulted from a discrete membrane, whereas 13 had complex forms of LVOT obstruction. Fully anesthetized and monitored patients were examined with 5 MHz TEE probes appropriate to the size of the patient. In the 14 patients with discrete LVOT obstruction, discrete membranes were identified by TEE in all; gradients ranged from 36 to 75 mm Hg. In 13 of 14 patients, postbypass TEE demonstrated removal of the membrane and excellent relief of gradients. In one of these patients, TEE demonstrated a small ventricular septal defect acquired during resection; the patient was returned to bypass for closure. In one patient, return to bypass for further resection of LVOT obstruction was prompted by TEE demonstration of a high residual gradient. In the 13 patients with complex LVOT obstruction, TEE demonstrated the complexity of LVOT obstruction in all. Gradients ranged from 4 to 95 mm Hg. Although this information was used in surgical planning, five patients had high residual gradients after bypass and underwent further resection. An additional two were returned to bypass for mitral valve replacement. Overall, 8 of 27 patients (29.6%) were returned to bypass based on TEE demonstration of residual anatomic or hemodynamic abnormalities. This occurred significantly more frequently in complex LVOT obstruction than in discrete LVOT obstruction (p = 0.045). We conclude that intraoperative TEE has substantial utility in the demonstration of site, mechanism, and severity of LVOT obstruction and for surgery designed to relieve LVOT obstruction. We believe that TEE should be an integral part of surgical management of LVOT obstruction.

Adolescent↗

[Septal ablation in the treatment of hypertrophic myocardiopathy].

Hypertrophic cardiomyopathy is a relative frequent disease and probably the most common genetic transmitted cardiovascular disease. Fortunately, the more aggressive varieties of the disease represent the less common manifestation of it. Outflow left ventricular obstruction is present in about 25 to 30% of the cases. Recently, septal ablation by means of the selective alcohol injection in left anterior descendent septal branches was introduced as a therapeutic alternative in cases associated with left ventricular outflow obstruction. Results with this technique have been encouraging with a success rate over 90%, and a low rate incidence of complications and mortality. These results are similar to those of surgical myectomy. We review indications, technique, and results obtained with this procedure.

Cardiomyopathy, Hypertrophic↗

Right ventricular outflow tract obstruction due to extrinsic compression by non-Hodgkin's lymphoma: importance of echocardiographic diagnosis and follow up.

Acquired right ventricular outflow tract obstruction due to extrinsic compression of the pulmonary artery is a rare manifestation of non-Hodgkin's lymphoma (NHL). We report a case of a 17 year old boy who was referred for evaluation of a large anterior mediastinal mass, causing dyspnea and cough and resulting in a harsh systolic murmur. Echocardiography demonstrated compression of the pulmonary artery by the mass, with a severe pressure gradient. Biopsy revealed intermediate grade, diffuse large cell NHL. Systemic chemotherapy rapidly led to a significant decrease in the size of the mass, and virtual disappearance of the pressure gradient. In this report, the use of echocardiography for diagnosis and follow up of extracardiac tumors is reviewed. It is suggested that this technique may also be useful for the routine staging of mediastinal lymphomas because of the potential consequences of clinically undetectable hemodynamic compromise.

Adolescent↗

Long-term results of the Konno procedure for complex left ventricular outflow tract obstruction.

OBJECTIVE: This study was undertaken to determine long-term clinical and echocardiographic outcomes after the Konno procedure. METHODS: Fifty-three patients who underwent the Konno procedure between January 1, 1980, and January 1, 2004, were reviewed. RESULTS: Mean age at operation was 19 years (range, 1-65 years). Indications were as follows: complex subaortic or tunnel stenosis in 22 (41%), multilevel left ventricular outflow tract obstruction in 20 (38%), and aortic valve stenosis or hypoplasia in 11 (21%). Before the Konno procedure, 66 operations were performed in 41 (77%) patients. Thirty-three (62%) patients had greater than New York Heart Association class I symptoms preoperatively. A mechanical aortic valve was implanted in 40 (75%), a homograft in 10 (19%), and a xenograft prosthesis in 3 (6%). Mortality at 30 days was 8% (n = 4). Survival at 10 years was 86%. Risk factors for overall mortality were New York Heart Association class (hazard ratio 2.22, P = .04) and longer bypass time (hazard ratio 1.93/hour, P = .04). The cumulative probability of aortic valve reoperation was 19% at 5 years and 39% at 10 years, occurring in 15 patients at a median of 3.8 years. The average left ventricular outflow tract mean gradients were 19 mm Hg at 1 year (n = 9), 13 mm Hg at 1 to 3 years (n = 9), and 13 mm Hg at 3 to 5 years (n = 5). Pulmonary regurgitation was detected in 6 patients. Pulmonary valve replacement was performed in 3 (6%). At the date of last contact, all patients for whom data was available were in New York Heart Association functional class I or II. CONCLUSION: The Konno procedure is effective, allowing both long-term reduction of left ventricular outflow tract obstruction and improvement in functional class. Prosthetic aortic valve and native pulmonary valve complications may necessitate reoperation.

Adolescent↗

Usefulness of color-flow Doppler in diagnosing and in differentiating supracristal ventricular septal defect from right ventricular outflow tract obstruction.

Color-flow Doppler is used for special localization of cardiac flows. The transeptal jet in supracristal ventricular septal defect (VSD) is directed toward the pulmonary valve and is often difficult to distinguish from the right ventricular (RV) outflow tract flow. Pulsed- and continuous-wave Doppler can misread the VSD jet as a stenotic lesion in the RV outflow tract. This study describes the color-flow Doppler characteristics of supracristal VSD and determines if color-flow Doppler can differentiate supracristal VSD jets from RV outflow tract flow. The study group comprised 28 patients ranging in age from 3 days to 23 years (mean 6.4), with catheter-diagnosed supracristal VSD in 14, isolated pulmonary valve stenosis in 10 and RV infundibular obstruction in 4. The echocardiographic Doppler and color-flow Doppler data of all patients were reviewed without knowledge of catheterization diagnosis. In all patients with supracristal VSD, color-flow Doppler revealed an abnormal transeptal jet directed toward the pulmonary valve that occurred 5 to 10 ms before RV outflow tract flow was identified. VSD and RV outflow tract jet could be differentiated by pulsed- and continuous-wave Doppler alone in 10 of 14 patients (71%). In 4 patients, differentiation was possible only with color-flow Doppler and electrocardiographic gating. Associated aortic regurgitation, or a fistula, or both, were detected in 6 patients. Pulsed- and continuous-wave Doppler with or without color-flow Doppler correctly identified the level of obstruction in all patients with RV outflow tract lesions (14 of 14). Supracristal VSD jet occurs in early systole and is directed toward the pulmonary valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Cardiogenic shock due to dynamic left ventricular outflow tract obstruction as a mechanical complication of acute myocardial infarction].

We report the clinical case of a 77-years-old woman with cardiogenic shock caused by dynamic left ventricular outflow tract (LVOT) obstruction that appeared after anterior acute myocardial infarction. Dynamic LVOT obstruction has been reported in various circumstances aside from hypertrophic obstructive cardiomyopathy, such as acute myocardial infarction. In a patient with cardiogenic shock and a heart murmur after acute myocardial infarction, an acute mechanical complication, ventricular septal defect, and acute mitral regurgitation must be ruled out because the treatment of these conditions differs completely. We describe the diagnostic and therapeutic measures used in the diagnosis and treatment of this complication.

Aged↗