New treatment strategies for hypertrophic obstructive cardiomyopathy: alcohol ablation of the septum: the new gold standard?
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Hypertrophic cardiomyopathy is a primary myocardial disorder with an autosomal pattern of inheritance characterized by inappropriate myocardial hypertrophy. Annual mortality has been reported to be 1% to 2% and sudden death represents the most common cause. Treatment strategies are 1) medical therapy in patients with mild to moderate symptoms, 2) reduction of septal hypertrophy by surgical myectomy or alcohol ablation, and 3) implantation of an automatic cardioverter-defibrillator in the presence of non-sustained ventricular tachyarrhythmias. A debate has been started on whether surgical myectomy or alcohol ablation of the septum is the appropriate treatment for hypertrophic obstructive cardiomyopathy. Surgical (transaortic) myectomy has been the gold standard in the past 20 to 30 years for treatment of symptomatic patients with significant hemodynamic outflow tract obstruction. However, modern interventional technologies allow reduction of the myocardial septum by injection of alcohol into the first or second septal branch under guidance of two-dimensional (2D)-contrast echocardiography. This percutaneous technique not only has a lower morbidity than surgical myectomy but can be guided precisely by 2D echocardiography. One potential complication is transient (<30%) or permanent (<10%) atrioventricular block III; however, this complication is relatively rare. A randomized trial comparing the two treatment modalities is lacking, and the chance is small that such a trial will be performed because alcohol ablation can be done with high success and low complication rates, leaving only complex interventions (with valvular reconstructions and so on) for surgical myectomy. (+info)
Left ventricular outflow tract obstruction due to anomalous insertion of papillary muscle.
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A 56-year-old man who complained of quadrantic hemianopsia was admitted to determine its etiology. Cerebral angiography revealed no organic stenosis. Echocardiography showed clear direct continuity between a hypertrophied anterolateral papillary muscle and the anterior mitral leaflet, and the left ventricular (LV) outflow tract (LVOT) was narrowed by the presence of an accessory papillary muscle. The LVOT obstruction caused an intra-LV pressure overload that resulted in LV concentric hypertrophy. Arrhythmia, such as paroxysmal atrial fibrillation (PAF), was thought to have caused a cerebral embolism. Mitral valve replacement (MVR), septal myectomy, and myectomy of the abnormal papillary muscle were performed, and complete release of the LVOT obstruction was accomplished. Anomalous insertion of papillary muscle is a rare cause of LVOT obstruction. Echocardiography was useful in identifying the papillary muscle malformation, and surgery was completely curative. (+info)
Surgical treatment for primary cardiac leiomyosarcoma causing right ventricular outflow obstruction.
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A 55-year-old man was admitted to another hospital because of dry cough and dyspnea that rapidly worsened before admission. Chest computed tomography revealed a low-density mass that nearly obstructed the main pulmonary arterial trunk. Pulmonary thromboembolism was suspected and treated with catheter-directed thrombolysis therapy. Despite optimal thrombolysis and anticoagulant therapy, his symptoms persisted. He was referred for further examination and possible surgery for presumed pulmonary thromboembolism. The mass appeared more likely to be a tumor than a thrombus on careful analysis of the magnetic resonance imaging. At surgery, the anterior wall of the main pulmonary arterial trunk, the pulmonary valve, annulus, and the right ventricular outflow tract were all invaded by what was found to be a tumor and were resected under conventional cardiopulmonary bypass. The resected area was reconstructed with a 25-mm-diameter bioprosthetic valve and Xenomedica patch. Final pathological diagnosis was primary cardiac leiomyosarcoma involving the pulmonary valve. Postoperative course was uneventful, and he was discharged 11 days after surgery without adjuvant therapy because he refused it. Ten months later, the patient was well, but a chest X-ray revealed some coin lesions in the bilateral lung fields that were thought to be metastatic tumor. (+info)
Amelioration of hypertrophic cardiomyopathy using nonsurgical septal ablation in a cirrhotic patient prior to liver transplantation.
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A 53-year-old male with hepatitis C cirrhosis, who had been refused liver transplantation because of hypertrophic cardiomyopathy (HC), underwent nonsurgical septal ablation using alcohol with resolution of his ventricular outflow obstruction. This patient was able to subsequently undergo a successful deceased donor liver transplantation. This is the first reported case of alcohol induced septal ablation being performed in a cirrhotic patient with HC. Such nonsurgical procedures may be attractive in cirrhotic patients who are refused access to liver transplantation because of high surgical risk. (+info)
Left heart growth, function, and reintervention after balloon aortic valvuloplasty for neonatal aortic stenosis.
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BACKGROUND: Transcatheter balloon aortic valvuloplasty (BAVP) has become the first-line treatment for critical aortic stenosis (AS) in neonates. However, little is known about the growth and function of left heart structures or about patterns of reintervention on the left heart after neonatal BAVP. METHODS AND RESULTS: Between 1985 and 2002, 113 patients underwent neonatal BAVP at < or =60 days of age. There were 16 early deaths (14%), with a significant decrease from 1985 to 1993 (22%) to 1994 to 2002 (4%), and 6 patients had successful early conversion to a univentricular circulation. In the short term, the mean relative gradient reduction was 54+/-26%, and significant aortic regurgitation (AR) developed in 15% of patients. The 91 early survivors with a biventricular circulation were followed up for 6.3+/-5.3 years, during which time there was a steady increase in the frequency of significant AR. Freedom from moderate or severe AR was 65% at 5 years. In almost all patients with a baseline aortic annulus z score less than -1, the annulus diameter increased to within the normal range within 1 to 2 years. Similarly, left ventricular (LV) end-diastolic dimension z scores, which ranged from -5 to 7.5 before BAVP, normalized within 1 to 2 years in nearly all patients with a predilation z score less than -1. Among early survivors with a biventricular circulation, reintervention-free survival on the LV outflow tract was 65% at 1 year and 48% at 5 years, with younger age, higher pre- and post-BAVP gradients, and a larger balloon-annulus diameter ratio associated with decreased reintervention-free survival (P<0.01). Seventeen surgical interventions were performed on the aortic valve in 15 patients, including replacement in 7. Survival free from aortic valve replacement was 84% at 5 years. CONCLUSIONS: BAVP for AS during the first 60 days of life results in short-term relief of AS in the majority of patients. Among early survivors, initially small left heart structures may be associated with worse subacute outcomes but typically normalize within 1 year. Reintervention for residual/recurrent AS or iatrogenic AR is relatively common, particularly during the first year after BAVP, but aortic valve replacement during early childhood is seldom necessary. (+info)
Inheritance analysis of congenital left ventricular outflow tract obstruction malformations: Segregation, multiplex relative risk, and heritability.
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The left ventricular outflow tract (LVOTO) malformations, aortic valve stenosis (AVS), coarctation of the aorta (COA), and hypoplastic left heart (HLH) constitute a mechanistically defined subgroup of congenital heart defects that have substantial evidence for a genetic component. Evidence from echocardiography studies has shown that bicuspid aortic valve (BAV) is found frequently in relatives of children with LVOTO defects. However, formal inheritance analysis has not been performed. We ascertained 124 families by an index case with AVS, COA, or HLH. A total of 413 relatives were enrolled in the study, of which 351 had detailed echocardiography exams for structural heart defects and measurements of a variety of aortic arch, left ventricle, and valve structures. LVOTO malformations were noted in 30 relatives (18 BAV, 5 HLH, 3 COA, and 3 AVS), along with significant congenital heart defects (CHD) in 2 others (32/413; 7.7%). Relative risk for first-degree relatives in this group was 36.9, with a heritability of 0.71-0.90. Formal segregation analysis suggests that one or more minor loci with rare dominant alleles may be operative in a subset of families. Multiplex relative risk analysis, which estimates number of loci, had the highest maximum likelihood score in a model with 2 loci (range of 1-6 in the lod-1 support interval). Heritability of several aortic arch measurements and aortic valve was significant. These data support a complex but most likely oligogenic pattern of inheritance. A combination of linkage and association study designs is likely to enable LVOTO risk gene identification. This data can also provide families with important information for screening asymptomatic relatives for potentially harmful cardiac defects. (+info)
Electrocardiographic and electrophysiologic characteristics of ventricular tachycardia originating within the pulmonary artery.
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OBJECTIVES: We investigated the electrocardiographic (ECG) and electrophysiologic characteristics of ventricular tachycardia (VT) originating within the pulmonary artery (PA). BACKGROUND: Radiofrequency catheter ablation (RFCA) is routinely applied to the endocardial surface of the right ventricular outflow tract (RVOT) in patients with idiopathic VT of left bundle branch block morphology. It was recently reported that this arrhythmia may originate within the PA. METHODS: Activation mapping and ECG analysis were performed in 24 patients whose VTs or ventricular premature contractions (VPCs) were successfully ablated within the PA (PA group) and in 48 patients whose VTs or VPCs were successfully ablated from the endocardial surface of the RVOT (RV-end-OT group). RESULTS: R-wave amplitudes on inferior ECG leads, aVL/aVR ratio of Q-wave amplitude, and R/S ratio on lead V(2) were significantly larger in the PA group than in the RV-end-OT group. On intracardiac electrograms, atrial potentials were more frequently recorded in the PA group than in the RV-end-OT group (58% vs. 12%; p < 0.01). The amplitude of local ventricular potentials recorded during sinus rhythm within the PA was significantly lower than that recorded from the RV-end-OT (0.62 +/- 0.56 mV vs. 1.55 +/- 0.88 mV; p < 0.01). CONCLUSIONS: Ventricular tachycardia originating within the PA has different electrocardiographic and electrophysiologic characteristics from that originating from the RV-end-OT. When mapping the RVOT area, the catheter may be located within the PA if a low-voltage atrial or local ventricular potential of <1-mV amplitude is recorded. Heightened attention must be paid if RFCA is required within the PA. (+info)
Total relief of severe left ventricular outflow obstruction after spontaneous rupture of chordae tendineae in a patient with hypertrophic cardiomyopathy.
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In hypertrophic cardiomyopathy (HCM), rupture of mitral chordae tendineae is infrequent and causes acute haemodynamic deterioration. A 38 year old male patient had chordae rupture leading to prolapse of both mitral leaflets and severe regurgitation, without change in symptomatic status. One year before, he had had mild mitral regurgitation and a resting left ventricle outflow tract of 105 mm Hg that disappeared in the present evaluation. In this unique case, worsening of mitral regurgitation was counterbalanced by total relief of the severe obstruction. This case report highlights the role of the mitral valve apparatus in the genesis of obstruction in HCM, further stimulating surgical techniques in which mitral repair can be the main procedure. (+info)