ABSTRACT
BACKGROUND: To study heart rate variability (HRV) in patients operated for tetralogy of Fallot (ToF) and to identify any correlation between HRV and ventricular tachycardia (VT). PATIENTS AND METHODS: We studied HRV in 23 consecutive patients operated for ToF (mean age 14 +/- 6.6 years; mean follow-up 10.6 +/- 5.2 years). Seven patients had non-sustained VT on Holter monitoring. Two control groups were included: 18 healthy subjects and 15 patients operated for other congenital heart disease. There were no differences in age, age at surgery (in the operated groups), follow-up, and mean heart rate between the three groups. Four time and four frequency domain indices were calculated: mean duration of RR intervals, standard deviation of all RR intervals (SD), square root of the mean squared differences of successive RR intervals (r-MSSD), percent of differences between adjacent RR intervals (pNN50), total power (TP), low frequency (LF), high frequency (HF), and LF/HF ratio. RESULTS: HRV indices were identical in the two control groups but were significantly reduced in patients with ToF. Within the patients who had been operated on for ToF, HRV indices were significantly lower in the seven with non-sustained VT than in those without arrhythmias: SD (95 +/- 15 vs. 135 +/- 54 ms; p = 0.01), r-MSSD (26 +/- 9 vs. 45 +/- 20 ms; p = 0.03), pNN50 (4.4 +/- 3.4 vs. 16.5 +/- 12.5%; p = 0.001) and HF (111 +/- 97 vs. 352 +/- 291 ms(2); p = 0.009). Using stepwise multivariate regression analysis, pNN50, age at surgery, degree of pulmonary regurgitation and higher right/left ventricular ratio were independent predictive variables for VT (p < 0.0001; r(2) = 0.85). CONCLUSIONS: ToF patients, particularly those with ventricular arrhythmias, have significant impairment of sympatho-vagal balance, characterized by a reduction of vagal drive.
Subject(s)
Autonomic Nervous System Diseases/diagnosis , Heart Rate , Risk Assessment/methods , Tachycardia, Ventricular/diagnosis , Tetralogy of Fallot/diagnosis , Tetralogy of Fallot/surgery , Adolescent , Autonomic Nervous System Diseases/etiology , Cardiovascular Surgical Procedures/adverse effects , Child , Electrocardiography, Ambulatory , Female , Humans , Male , Prognosis , Tachycardia, Ventricular/etiology , Tetralogy of Fallot/complications , Treatment OutcomeABSTRACT
OBJECTIVES: We report our experience of percutaneous valve insertion in pulmonary position in humans. BACKGROUND: Over the past 40 years, prosthetic conduits have been developed to surgically establish continuity between the right ventricle and the pulmonary artery. However, stenosis and insufficiency of the conduit due to valvular degeneration or panus ingrowth frequently occur, limiting patients' lifespan. Percutaneous stenting of conduits has recently emerged as a technique for delaying surgical replacement, but it creates a pulmonary regurgitation when crossing the valve. METHODS: Seven children and one adult with stenosis and/or insufficiency of the pulmonary graft underwent percutaneous implantation of a bovine jugular valve in pulmonary position. RESULTS: Percutaneous pulmonary valve (PV) replacement was successful in all patients. No complications occurred in early follow-up. Angiography, hemodynamic studies and echocardiography after the procedure showed no significant regurgitation of the implanted valve. Implantation was effective in relieving the obstruction in five patients. All patients showed improvement in their clinical status at the latest follow-up (mean 10.1 months). CONCLUSIONS: Non-surgical insertion of the PV is possible without any major complications. This new technique may have an important role in the management of conduit obstructions and pulmonary regurgitation.
Subject(s)
Bioprosthesis , Cardiac Catheterization/instrumentation , Heart Valve Prosthesis Implantation/instrumentation , Minimally Invasive Surgical Procedures/instrumentation , Pulmonary Valve Insufficiency/surgery , Pulmonary Valve Stenosis/surgery , Adolescent , Adult , Child , Echocardiography, Doppler , Female , Humans , Male , Prosthesis Design , Pulmonary Valve Insufficiency/diagnostic imaging , Pulmonary Valve Stenosis/diagnostic imaging , Reoperation , Ventricular Outflow Obstruction/diagnostic imaging , Ventricular Outflow Obstruction/surgeryABSTRACT
Differentiation between a cleft of the mitral valve and the cleft of the left side of an atrioventricular septal defect--a lesion commonly found in patients with Down's syndrome--is surgically important since the distribution of the conduction tissue varies between the 2 lesions. We sought to determine if cleft of the mitral valve occurs also in patients with Down's syndrome. We studied 5 patients with Down's syndrome and cleft of the mitral valve followed in our institution. Echocardiography showed in all 5 patients a cleft dividing the anterior (aortic) leaflet of mitral valve with normal papillary muscle position, mural leaflet size, and ratio of the inlet/outlet dimension of the left ventricle. Associated cardiac lesions were present in all 5 patients: perimembranous ventricular septal defect in 3, ostium secundum atrial septal defect in 2 and patent ductus arteriosus in 2 patients. During the 5.6 years (0.2-11) of the follow-up period, surgical repair of the cleft was never indicated since the mitral regurgitation through the cleft remained mild or absent in all the patients. Two patients underwent closure of a ventricular septal defect, with atrial septal defect closure in one and ductal ligation in 2. One patient died suddenly at home, without evidence of a cardiac cause. In conclusion, a cleft of the mitral valve has important developmental and morphologic differences with atrioventricular septal defect and may occur in patients with Down's syndrome. If surgical repair of the cleft or of associated cardiac lesion is indicated, it is necessary to distinguish it from atrioventricular septal defect where the conduction axis is displaced posteriorly and may be exposed during surgery.
