Signal-morphology impedance cardiography during incremental cardiopulmonary exercise testing in pulmonary arterial hypertension.

BACKGROUND: Haemodynamic responses to exercise are related to physical impairment and worse prognosis in patients with pulmonary arterial hypertension (PAH). It is clinically relevant, therefore, to investigate the practical usefulness of non-invasive methods of monitoring exercise haemodynamics in this patient population. METHODS: Using a novel impedance cardiography (ICG) approach that does not require basal impedance estimations and relies on a morphological analysis of the impedance signal (Signal-Morphology-ICG(™)), stroke volume (SV) and cardiac index (CI) were evaluated in 50 patients and 21 age-matched controls during a ramp-incremental cardiopulmonary exercise testing. RESULTS: Technically unacceptable readings were found in 12 of 50 (24%) patients. In the remaining subjects, early decrease (N = 9) or a 'plateau' in SV (N = 8) and Δ (peak-unloaded exercise) SV <10 ml were markers of more advanced PAH (P<0.05). ΔCI ≤ 1.5-fold and early estimated lactate threshold were the only independent predictors of a severely reduced peak oxygen uptake (VO(2)) in patients (R(2) = 0.71, P<0.001). The finding of ΔCI ≤ 1.5-fold plus peak VO(2) < 50% predicted was associated with a number of clinical and functional markers of disease severity (P<0.001). In addition, abnormal SV responses and ΔCI ≤ 1.5-fold were significantly related to 1-year frequency of PAH-related adverse events (death and balloon atrial septostomy, N = 8; P<0.05). CONCLUSIONS: 'Qualitative' and 'semi-quantitative' signal-morphology impedance cardiography(™) (PhysioFlow(™)) during incremental exercise provided clinically useful information to estimate disease severity and short-term prognosis in patients with PAH in whom acceptable impedance signals could be obtained.

Nova técnica: operação de Norwood com perfusão regional cerebral e coronariana / New technique: Norwood operation with regional cerebral and coronary perfusion

Objetivo: Avaliar o resultado imediato da operação de Norwood modificado com nova técnica de perfusão regional cerebral (PRCeA) anterógrada associado a perfusão regional coronariana (PRCoR) retrógrada em substituição à parada circulatória total com hipotermia profunda em crianças portadoras da Síndrome da Hipoplasia do Coração Esquerdo (SHCE) com aorta ascendente extremamente hipoplásica (AH). Métodos: No período de dezembro de 2006 a fevereiro de 2008, a operação de Norwood modificado com tubo entre o ventrículo direito e as artérias pulmonares ou shunt tipo Sano foi realizada em oito crianças portadoras de SHCE e aorta ascendente com diâmetro inferior a 3 mm, (quatro do sexo masculino e quatro do sexo feminino) com idade média de 9,2 dias (variando de 1 a 29 dias) e peso médio de 3,3 kg (variando de 2,7 a 3,8 kg). Utilizada CEC e hipotermia a 25ºC com duas cânulas venosas e anastomose de um enxerto de politetrafluoretileno com a artéria inominada utilizado como linha arterial e para PRCeA. A PRCoR foi realizada por meio de um desvio na linha arterial e colocação de um cateter na aorta ascendente. Foram analisados o resultado cirúrgico imediato e a presença de alterações neurológicas nesse período. Resultados: O resultado cirúrgico imediato revelou mortalidade de 25 por cento e ausência de comprometimento neurológico ao exame clínico. Conclusão: A operação de Norwood modificado pode ser realizada com PRCeA e PRCoR em crianças com SHCE e AH com resultado cirúrgico imediato satisfatório e ausência de complicações neurológicas.

Objective: To assess the immediate result of the modified Norwood procedure with new technique of anterograde regional cerebral perfusion (ARCeP) and retrograde regional coronary perfusion (RRCoP) in substitution of profound hypothermia and circulatory arrest in children with hypoplastic left heart syndrome (HLHS) with extremely hypoplastic ascending aorta (HA). Methods: In the period of December of 2006 to February 2008 the modified Norwood procedure with tube between the right ventricle and pulmonary arteries or Sano shunt was performed in eight children with HLHS and with ascending aorta diameter less than 3 mm, (four male and four female) with median age of 9.2 days (ranging from 1 to 29 days) and median weigh of 3.3 kg (ranging from 2.7 to 3.8 kg). We used cardiopulmonary bypass and hypothermia at 25ºC with two venous cannulas and suture with a polytetrafluoroethylene graft sutured to the innominate artery as an arterial line and used to ARCeP. The RRCoP was performed by a deviation in the arterial line and placement of a catheter in the ascending aorta. The immediate surgical results and the clinical neurological manifestation were assessed. Results: The immediate surgical results revealed mortality of 25 percent and there were absence of neurological injury at clinical examination. Conclusions: The modified Norwood procedure can be accomplished with ARCeP and RRCoP in children with HLHS with HA with satisfactory immediate surgical result and without neurological complications.

New technique: Norwood operation with regional cerebral and coronary perfusion.

OBJECTIVE: To assess the immediate result of the modified Norwood procedure with new technique of anterograde regional cerebral perfusion (ARCeP) and retrograde regional coronary perfusion (RRCoP) in substitution of profound hypothermia and circulatory arrest in children with hypoplastic left heart syndrome (HLHS) with extremely hypoplastic ascending aorta (HA). METHODS: In the period of December of 2006 to February 2008 the modified Norwood procedure with tube between the right ventricle and pulmonary arteries or Sano shunt was performed in eight children with HLHS and with ascending aorta diameter less than 3 mm, (four male and four female) with median age of 9.2 days (ranging from 1 to 29 days) and median weigh of 3.3 kg (ranging from 2.7 to 3.8 kg). We used cardiopulmonary bypass and hypothermia at 25 masculineC with two venous cannulas and suture with a polytetrafluoroethylene graft sutured to the innominate artery as an arterial line and used to ARCeP. The RRCoP was performed by a deviation in the arterial line and placement of a catheter in the ascending aorta. The immediate surgical results and the clinical neurological manifestation were assessed. RESULTS: The immediate surgical results revealed mortality of 25% and there were absence of neurological injury at clinical examination. CONCLUSIONS: The modified Norwood procedure can be accomplished with ARCeP and RRCoP in children with HLHS with HA with satisfactory immediate surgical result and without neurological complications.