Disease relevance of Ventricular Outflow Obstruction

• In patients with hypertrophic cardiomyopathy, efforts to attribute sudden death to the cardiac index, left ventricular end-diastolic pressure, left ventricular outflow obstruction, ejection fraction, age, symptomatic state and septal thickness have been unrewarding [1].
• Transient mitral regurgitation disappeared completely in 12/62 patients: five had temporary impairment of LV function, two had reduced filling of the heart, one had left ventricular outflow obstruction exacerbated by isoproterenol and nitroglycerin, two had ventricular ectopic rhythms, and two epicardial pacing [2].
• All patients had major associated cardiac abnormalities: approximately one third had ventricular septal defect with patent ductus arteriosus, one third had complex ventricular septal defect with left ventricular outflow obstruction, and one third had complex intracardiac lesions incompatible with survival [3].
• Potential risk factors included location of the largest ventricular septal defect, presence of additional ventricular septal defects, ventricular outflow obstruction or hypoplasia, or both ventricular outflow obstruction and hypoplasia, previous palliation, and type of definitive operation [4].
• Six patients had a large left-to-right shunt though a ventricular septal defect (VSD), two patients had left ventricular outflow obstruction, two patients had mitral insufficiency, and one patient had mitral stenosis [5].

High impact information on Ventricular Outflow Obstruction

• Independent risk factors analyzed included location of the main VSD, presence of additional VSDs, coarctation, ventricular outflow obstruction, ventricular hypoplasia, age at operation, operation before 1985, previous palliation, and type of definitive operation [6].
• Furthermore, in the Caucasian kindred, all patients had nonobstructive hypertrophic cardiomyopathy, but most of the patients in the Korean kindred had left ventricular outflow obstruction [7].
• The present study examines prospectively the ability of dual-chamber (DDD) pacing to improve symptoms and relieve left ventricular outflow obstruction in such patients [8].
• Case 1. Right ventricular outflow obstruction caused by metastatic hepatocellular carcinoma [9].
• METHODS: Forty-one consecutive NSRT patients at Baylor College of Medicine with one-year follow-up were compared with age- and gradient-matched septal myectomy patients at the Mayo Clinic. All patients had left ventricular outflow obstruction with a resting gradient > or =40 mm Hg and none had concomitant procedures [10].

Chemical compound and disease context of Ventricular Outflow Obstruction

• These results indicate that verapamil can significantly decrease left ventricular outflow obstruction in patients with hypertrophic cardiomyopathy and thus may provide an important new therapeutic agent in the treatment of this disorder [11].
• Typical ESC was observed, but no SAM or left ventricular outflow obstruction, in five of the eight dogs treated with isoproterenol [12].
• Percent-predicted peak VO(2) was similar in patients with and without resting left ventricular outflow obstruction [13].
• The development of left ventricular outflow obstruction was defined as a late-peaking Doppler velocity profile that exceeded baseline outflow velocity by at least 1 m/sec in 104 consecutive patients undergoing dobutamine stress echocardiography [14].
• Use of Doppler echocardiography and amyl nitrite inhalation to characterize left ventricular outflow obstruction in hypertrophic cardiomyopathy [15].

Anatomical context of Ventricular Outflow Obstruction

• Anomalous insertion of papillary muscle directly into anterior mitral leaflet in hypertrophic cardiomyopathy. Significance in producing left ventricular outflow obstruction [16].
• This study looked at echocardiographic predictors of left ventricular outflow obstruction after primary neonatal repair of interrupted aortic arch and ventricular septal defect [17].
• RESULTS: Seventeen fetuses were confirmed to have a ventricular septal defect and an overriding aorta with varying degrees of right ventricular outflow obstruction after delivery [18].
• A rare case of single, pedunculated, ball-like rhabdomyoma of the pulmonary valve, causing moderate right ventricular outflow obstruction in an infant with tuberous sclerosis, is presented [19].
• Total relief of severe left ventricular outflow obstruction after spontaneous rupture of chordae tendineae in a patient with hypertrophic cardiomyopathy [20].

Gene context of Ventricular Outflow Obstruction

• Patients who subsequently develop left ventricular outflow obstruction have the greatest degree of ventricular contraction and VSD diminution early after surgery [21].
• We identified 12 infants with acid maltase deficiency who had a similar clinical presentation but less severe cardiomyopathy and absence of left ventricular outflow obstruction, and 9 of 12 had longer survival with assisted ventilation and supplemental intubation [22].
• Left ventricular inflow obstruction associated with persistent left superior vena cava and dilated coronary sinus [23].

Analytical, diagnostic and therapeutic context of Ventricular Outflow Obstruction

• Echocardiography demonstrated aneurysmal dilation of the native pericardial patch used for VSD closure, resulting in right ventricular inflow obstruction [24].

References