ALEXANDRE LEMOS BORTOLOTTO
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- ACUTE PULMONAR EDEMA AND VENTRICULAR DYSFUNCTION DUE ADRENERGIC MYOCARDITIS ASSOCIATED TO PHEOCHROMOCYTOMA(2019) BORTOLOTTO, Luiz Aparecido; BORTOLOTTO, Alexandre L.; CASTRO, Rafael; SOUSA, Maria T. S.; SOEIRO, Alexandre; PEREIRA, Adelaide
- STRESS-INDUCED T-WAVE HETEROGENEITY WITH REGADENOSON DETECTS CLINICALLY SIGNIFICANT CORONARY ARTERY STENOSIS(2019) SILVA, Bruna Araujo; NEARING, Bruce; BORTOLOTTO, Alexandre; MARUM, Alexandre; GERVINO, Ernest; VERRIER, Richard
- Optimizing flecainide plasma concentration profile for atrial fibrillation conversion while minimizing adverse ventricular effects by rapid, low-dose intratracheal or intravenous administration(2019) MARUM, Alexandre A.; SILVA, Bruna A.; BORTOLOTTO, Alexandre L.; SILVA, Anderson C.; ANTONIO, Victor Z. de; BELARDINELLI, Luiz; VERRIER, Richard L.Background: We investigated whether rapid administration of a low dose of flecainide, either intratracheally or intravenously (IV), could accelerate conversion of atrial fibrillation (AF) while reducing adverse ventricular effects. Methods: Flecainide was delivered via intratracheal administration at 1.5 mg/kg bolus and compared to IV infusion at 1.0 mg/kg over 2 min (lower-dose, rapid) and 2.0 mg/kg over 10 min (ESC guideline) in closed-chest, anesthetized Yorkshire pigs. Catheters were fluoroscopically positioned in right atrium to measure atrial depolarization (P-a) duration and left ventricle (LV) to measure QRS complex duration and contractility (LV dP/dt) during atrial pacing at 140 beats/min. Flecainide was delivered intratracheally via a catheter positioned at the bifurcation of the main bronchi. AF was induced by intrapericardial administration of acetylcholine followed by burst pacing. Results: Flecainide reduced AF duration similarly by intratracheal and IV delivery. Peak plasma levels were comparable but T-max differed and coincided with peaks in P-a prolongation. The area under the curve indicating sustained plasma levels was greater for higher-dose, slow IV flecainide than for either intratracheal instillation (by 32%) or lower-dose, rapid IV infusion (by 88%). As a result, higher-dose, slow IV flecainide caused 58% (p < 0.03) and 48% (p < 0.006) greater increases in QRS complex duration and 61% and 96% (both, p < 0.02) greater reductions in contractility compared to intratracheal and lower-dose, rapid IV flecainide, respectively. Conclusion: Lower-dose, rapid flecainide, delivered either intratracheally or IV, optimizes the plasma concentration profile for effective conversion of AF while minimizing adverse effects on QRS complex duration and LV contractility.