Tetralogy of Fallot: Preoperative assessment with MR and CT imaging.

Tetralogy of Fallot has a broad anatomical spectrum. In mild forms of the condition the obstruction is only located in the right ventricular infundibulum, whereas in severe forms the pulmonary valve is atretic, the pulmonary arteries are absent and the lung is supplied by aorto-pulmonary collateral arteries. Surgical management differs from conventional surgery in the former situation, whereas in the latter it is complex and requires reconstruction of the pulmonary arteries (unifocalization) carried out in more than one stage and with a high morbidity rate. The key factors to establish before corrective surgery are the levels and degree of obstruction of the right ventricular outflow tract, the development of the pulmonary arteries and the presence of collateral arteries. The main role of magnetic resonance imaging along with that of computed tomography angiography are discussed and illustrated.

Comparison of Outcomes in Patients With Nonobstructive, Labile-Obstructive, and Chronically Obstructive Hypertrophic Cardiomyopathy.

Patients with nonobstructive hypertrophic cardiomyopathy (HC) are considered low risk, generally not requiring aggressive intervention. However, nonobstructive and labile-obstructive HC have been traditionally classified together, and it is unknown if these 2 subgroups have distinct risk profiles. We compared cardiovascular outcomes in 293 patients HC (96 nonobstructive, 114 labile-obstructive, and 83 obstructive) referred for exercise echocardiography and magnetic resonance imaging and followed for 3.3 ± 3.6 years. A subgroup (34 nonobstructive, 28 labile-obstructive, 21 obstructive) underwent positron emission tomography. The mean number of sudden cardiac death risk factors was similar among groups (nonobstructive: 1.4 vs labile-obstructive: 1.2 vs obstructive: 1.4 risk factors, p = 0.2). Prevalence of late gadolinium enhancement (LGE) was similar across groups but more non-obstructive patients had late gadolinium enhancement ≥20% of myocardial mass (23 [30%] vs 19 [18%] labile-obstructive and 8 [11%] obstructive, p = 0.01]. Fewer labile-obstructive patients had regional positron emission tomography perfusion abnormalities (12 [46%] vs nonobstructive 30 [81%] and obstructive 17 [85%], p = 0.003]. During follow-up, 60 events were recorded (36 ventricular tachycardia/ventricular fibrillation, including 30 defibrillator discharges, 12 heart failure worsening, and 2 deaths). Nonobstructive patients were at greater risk of VT/VF at follow-up, compared to labile obstructive (hazed ratio 0.18, 95% confidence interval 0.04 to 0.84, p = 0.03) and the risk persisted after adjusting for age, gender, syncope, family history of sudden cardiac death, abnormal blood pressure response, and septum ≥3 cm (p = 0.04). Appropriate defibrillator discharges were more frequent in nonobstructive (8 [18%]) compared to labile-obstructive (0 [0%], p = 0.02) patients. In conclusion, nonobstructive hemodynamics is associated with more pronounced fibrosis and ischemia than labile-obstructive and is an independent predictor of VT/VF in HC.

The dilemma of subaortic stenosis--a single center experience of 15 years with a review of the literature.

OBJECTIVE: The term "subaortic stenosis" includes a variety of obstructions of the left ventricular outflow tract (LVOT), ranging from a short (discrete) subvalvular membrane to long, tunnel-like narrowing. An association with other congenital lesions is frequent. We reviewed the reported literature and describe our results, analyzing the nomenclature of and risk factors for restenosis after surgical treatment. METHODS: From 1994 to 2009, 81 children (53 males, 28 females; median age: 57 months, range [ R]: 5-204) underwent surgical relief of a subaortic stenosis. Patients were divided, according to pathology, into short segment (group A, n = 42) and complex obstructions (group B, n = 39), with the latter including long segment stenosis and/or associated anomalies such as aortic coarctation, interrupted aortic arch or Shone's complex. RESULTS: Surgery resulted in a significant reduction of the gradient between the left ventricle and the aorta in both groups (Δ P group A: 51 ± 28 mmHg, group B: 46 ± 25 mmHg). There was no operative mortality. One patient died in the early postoperative period due to pericardial tamponade. Median follow-up was 90 months (R = 0.5-187). Twenty-five (31%) patients required reoperation because of recurrent stenosis after a median of 43 months (R = 0.5-128). Seven (16%) patients belonging to group A developed restenosis, and 18 (46%) in group B. Freedom from reoperation for all patients was 60% after 10 years. 10 (40%) of the patients of group B were ultimately treated with a Ross-Konno reconstruction of the LVOT. CONCLUSION: Despite adequate surgical resection, recurrence of subaortic stenosis within several years after initial surgical treatment is frequent, especially in patients with complex lesions. In cases requiring reoperation, the surgical therapy is often extensive, and even includes Ross-Konno reconstruction of the LVOT.

Hospital mortality in surgery for reconstruction outflow right ventricle with pulmonary homograft.

BACKGROUND: Hospital mortality for surgical reconstruction of the outflow of the right ventricle with pulmonary homograft is variable. OBJECTIVES: To identify risk factors associated with hospital mortality and clinical profile of patients. METHODS: Children underwent reconstruction of the outflow tract of right ventricle with pulmonary homograft. Analyzed as risk factors for the clinical, surgical and morphological aspects of the prosthesis. RESULTS: Ninety-two patients operated on between 1998 and 2005 presented mainly pulmonary atresia with ventricular septal defect and tetralogy of Fallot. Forty patients were treated in the first month of life. He needed 38 surgeries to Blalock Taussig due to clinical severity. The median age at surgery for total correction was 22 months, ranging from 1 to 157 months. Size pulmonary homograft ranging from 12 to 26 mm and length of bypass was 132 +/- 37 minutes. After surgery there were seventeen deaths (18% cases) on average 10.5 +/- 7.5 days. The predominant cause was multiple organ failure. In the univariate analysis between the types of heart disease, they found in favor of age at surgery, size of homograft, pulmonary valve Z value, CPB time, maintaining the integrity of the homograft and pulmonary tree change. There was no statistical difference in hospital mortality between the variables and the type of heart disease. CONCLUSION: The congenital obstructive right requires surgical care in the first days of life. The total correction surgery has a risk rate of 18% but there was no association with any variable studied.

Mortalidade hospitalar na cirurgia de reconstrução da via de saída do ventrículo direito com homeonxerto pulmonar / Hospital mortality in surgery for reconstruction outflow right ventricle with pulmonary homograft

FUNDAMENTO: Mortalidade hospitalar na cirurgia de reconstrução da via de saída do ventrículo direito com homoenxerto pulmonar é variável. OBJETIVOS: Identificar os fatores de risco associados à mortalidade hospitalar e ao perfil clínico dos pacientes. MÉTODOS: Estudo de crianças submetidas à reconstrução da via de saída do ventrículo direito com homoenxerto pulmonar. Analisados como fatores de risco as variáveis clínicas, cirúrgicas e de aspectos morfológicos da prótese. RESULTADOS: Noventa e dois pacientes foram operados entre 1998 e 2005, apresentando principalmente atresia pulmonar com comunicação interventricular e a tetralogia de Fallot. Quarenta pacientes foram atendidos no primeiro mês de vida. Necessitaram de 38 cirurgias de Blalock Taussig devido à gravidade clínica. A idade mediana na cirurgia de correção total foi de 22 meses, variando de 1 mês a 157 meses. O tamanho homoenxerto pulmonar variou de 12 a 26 mm e o tempo de extracorpórea foi 132 ± 37 minutos. Após a cirurgia houve 17 óbitos (18 por cento casos), em média 10,5 ± 7,5 dias após. A causa predominante foi falência de múltiplos órgãos. Na análise univariada entre os tipos de cardiopatia, estas deferiram na idade, momento da cirurgia, tamanho do homoenxerto, valor Z da valva pulmonar, tempo de circulação extracorpórea, manutenção da integridade do homoenxerto e alteração da árvore pulmonar. Não houve diferença estatística com relação à mortalidade hospitalar entre as variáveis e o tipo de cardiopatia. CONCLUSÃO: As cardiopatias obstrutivas do lado direito necessitam de atendimento cirúrgico nos primeiros dias de vida. A cirurgia de correção total apresenta risco de mortalidade de 18 por cento, mas não houve associação com nenhuma variável estudada.

BACKGROUND: Hospital mortality for surgical reconstruction of the outflow of the right ventricle with pulmonary homograft is variable. OBJECTIVES: To identify risk factors associated with hospital mortality and clinical profile of patients. METHODS: Children underwent reconstruction of the outflow tract of right ventricle with pulmonary homograft. Analyzed as risk factors for the clinical, surgical and morphological aspects of the prosthesis. RESULTS: Ninety-two patients operated on between 1998 and 2005 presented mainly pulmonary atresia with ventricular septal defect and tetralogy of Fallot. Forty patients were treated in the first month of life. He needed 38 surgeries to Blalock Taussig due to clinical severity. The median age at surgery for total correction was 22 months, ranging from 1 to 157 months. Size pulmonary homograft ranging from 12 to 26 mm and length of bypass was 132 ± 37 minutes. After surgery there were seventeen deaths (18 percent cases) on average 10.5 ± 7.5 days. The predominant cause was multiple organ failure. In the univariate analysis between the types of heart disease, they found in favor of age at surgery, size of homograft, pulmonary valve Z value, CPB time, maintaining the integrity of the homograft and pulmonary tree change. There was no statistical differencein hospital mortality between the variables and the type of heart disease. CONCLUSION: The congenital obstructive right requires surgical care in the first days of life. The total correction surgery has a risk rate of 18 percent but there was no association with any variable studied.

[Therapy and risk-stratification in hypertrophic cardiomyopathy--a current survey]. / Therapie und Risikostratifizierung der Hypertrophen Kardiomyopathie. Ein aktueller Uberblick.

Hypertrophic cardiomyopathy (HCM) is a relatively common disease of the cardiac sarcomere with broad heterogeneity in terms of the disease-causing gene mutation, phenotypic expression, therapy and prognosis. Besides the standard drug treatment, there are several therapeutic options available for severe refractory symptomatic HCM with obstruction. Dual-chamber pacing and transcoronary ablation of septal hypertrophy (TASH) have recently emerged as alternatives to myectomy. However, myectomy remains the current gold standard of therapy for HCM until the promising initial follow-up data for TASH can be transferred into a long-term follow-up period, or prospective randomized comparative trials between these therapies are available. However, even now, TASH represents an important therapeutic alternative in patients with relevant co-morbidities and a high operative risk. Despite significant gradient reduction and amelioration of clinical symptoms, none of these treatment strategies has a proven influence on the natural history of HCM. Hence, regarding the long-term prognosis of the disease, risk stratification of sudden cardiac death using non-invasive risk assessment has become of paramount importance, while genotyping might become the determinant and stratifying marker in the near future. At present, according to secondary prevention, treatment with an implanted cardioverter-defibrillator +/- amiodarone therapy is mandatory, while according to primary prevention treatment should particularly depend on the individual risk profile.

Effect of left ventricular outflow tract obstruction on clinical outcome in hypertrophic cardiomyopathy.

BACKGROUND: The influence of left ventricular outflow tract obstruction on the clinical outcome of hypertrophic cardiomyopathy remains unresolved. METHODS: We assessed the effect of outflow tract obstruction on morbidity and mortality in a large cohort of patients with hypertrophic cardiomyopathy who were followed for a mean (+/-SD) of 6.3+/-6.2 years. RESULTS: Of the 1101 consecutive patients, 273 (25 percent) had obstruction of left ventricular outflow under basal (resting) conditions with a peak instantaneous gradient of at least 30 mm Hg. A total of 127 patients (12 percent) died of hypertrophic cardiomyopathy, and 216 surviving patients (20 percent) had severe, disabling symptoms of progressive heart failure (New York Heart Association [NYHA] functional class III or IV). The overall probability of death related to hypertrophic cardiomyopathy was significantly greater among patients with outflow tract obstruction than among those without obstruction (relative risk, 2.0; P=0.001). The risk of progression to NYHA class III or IV or death specifically from heart failure or stroke was also greater among patients with obstruction (relative risk, 4.4; P<0.001), particularly among patients 40 years of age or older (P<0.001). Age-adjusted multivariate analysis confirmed that outflow tract obstruction was independently associated with an increased risk of both death related to hypertrophic cardiomyopathy (relative risk, 1.6; P=0.02) and progression to NYHA class III or IV or death from heart failure or stroke (relative risk, 2.7; P<0.001). The likelihood of severe symptoms and death related to outflow tract obstruction did not increase as the gradient increased above the threshold of 30 mm Hg. CONCLUSIONS: In patients with hypertrophic cardiomyopathy, left ventricular outflow tract obstruction at rest is a strong, independent predictor of progression to severe symptoms of heart failure and of death.

The surgical anatomy of the left ventricular outflow tract in hearts with ventricular septal defect and aortic arch obstruction.

BACKGROUND: Profound understanding of the left ventricular outflow tract (LVOT) anatomy is crucial to improve surgical results in patients with aortic arch obstruction, ventricular septal defect, and subaortic stenosis. METHODS: We studied the morphology of the LVOT in 32 postmortem hearts with aortic arch obstruction and a ventricular septal defect. In case of subaortic obstruction, the length of the subaortic muscular component was measured anteriorly and posteriorly within the left ventricle. RESULTS: Seven of the 32 hearts had no subaortic stenosis. Nine had aortic override, which caused LVOT narrowing. Sixteen hearts contained a subaortic shelf, downstream to the ventricular septal defect, which deviated into the left ventricle in 15. In 10 of these the shelf was muscular; in 6 it was a fibrous ridge. In cases with a muscular shelf, the posterior part was significantly shorter than the anterior part (p < 0.004). In 9 hearts the LVOT was further narrowed because of the abnormal relationship between the mitral valve and the subaortic shelf. CONCLUSIONS: The present study confirms the complexity of LVOT stenosis in aortic arch obstruction and ventricular septal defect and provides a better understanding of the options to achieve surgical relief.

Ventricular function after the arterial switch operation for transposition of the great arteries.

The theoretical advantages of anatomical repair have resulted in the widespread use of the arterial switch operation for transposition of the great arteries. However, preservation of systemic ventricular performance and late functional results have not been well documented. To evaluate late postoperative ventricular function, we reviewed 53 consecutive patients undergoing arterial switch operation for transposition of the great arteries with or without a ventricular septal defect over the 8-year period from March 1985 to 1993. Forty-two patients had simple transposition of the great arteries and 11 patients had associated ventricular septal defects that were closed at operation. Mean age at operation was 1.8 months (range, 1 day to 36 months), and mean patient weight was 3.8 kg (range, 1.8 to 15.6 kg). All but 8 patients were neonates. There were six operative deaths (11.3%, 6/53) and two late deaths during a median follow-up of 23 months (range, 0.1 to 99.5 months). Actuarial survival at 8 years was 83% +/- 6%. Left ventricular outflow tract obstruction has not been identified, and 9 patients (20%, 9/45) have right ventricular outflow tract gradients exceeding 20 mm Hg, 3 of whom have required reoperation. Eighteen patients have mild neo-aortic valve regurgitation. All survivors are currently in New York Heart Association class I, and are in sinus rhythm. Systolic left ventricular function is well preserved with ejection fractions greater than 0.60 in all survivors followed up for more than 4 months (41 patients). Left ventricular end-diastolic volume index is elevated in only 1 patient, a patient who had pulmonary artery banding as a neonate.(ABSTRACT TRUNCATED AT 250 WORDS)

[Surgical treatment of congenital obstruction of the left ventricular outflow tract]. / Kirursko lijecenje prirodene opstrukcije izlaznog dijela lijevog ventrikula.

This report presents the classification and all types of left ventricular outflow tract obstructions. The possibilities of operative therapies are surveyed as well. Results of surgical treatment in 34 patients with obstruction to left ventricular outflow are shown. The majority of patients underwent operation under extracorporeal circulation (84.4%), while the rest were operated by means of the inflow occlusion technique (14.7%). The obtained results were compared with those from the literature. The importance of echocardiographic evaluation of location of the left ventricular outflow tract obstruction and the appropriate choice of a surgical technique according to the patient's age are emphasized.