RESUMO
SUMMARY BACKGROUND: Investigation of syncope involves the use of electrophysiological study, particularly in patients with cardiac conduction disorder. There is conflicting evidence about the role of electrophysiological study in patients with Chagas disease. OBJECTIVE: The objective of this study was to evaluate the electrophysiological study findings in patients with Chagas disease and bundle branch block and/or divisional block presenting with syncope. METHODS: This is a retrospective study of patients with Chagas disease and cardiac conduction disorder who underwent electrophysiological study from 2017 to 2021 for the investigation of syncope in a tertiary hospital in São Paulo, Brazil. Those with non-interpretable ECG, known coronary artery disease, and/or other cardiomyopathies were excluded. HV interval and electrophysiological study-induced malignant ventricular arrhythmias data were analyzed. RESULTS: A total of 45 patients (60.2±11.29 years, 57.8% males) were included. The mean HV interval was 58.37 ms±10.68; 22.2% of the studied population presented an HV interval of ≥70 ms; and malignant ventricular arrhythmias were induced in 57.8% patients. The use of beta-blockers and amiodarone (p=0.002 and 0.036, respectively), NYHA functional class≥II (p=0.013), wide QRS (p=0.047), increased HV interval (p=0.02), Rassi score >6.5 (p=0.003), and reduced left ventricular ejection fraction (p=0.031) were associated with increased risk of inducible malignant ventricular arrhythmias. CONCLUSION: More than half of the patients with Chagas disease, syncope, and cardiac conduction disorder have inducible malignant ventricular arrhythmias. Prolonged HV interval was observed in only 20% of population. Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score were associated with increased risk of malignant ventricular arrhythmias.
RESUMO
Angiogenesis is the process through which new capillaries form from pre-existing capillaries and venules. Its occurrence depends on the migration of vascular endothelial cells which is inhibited by high levels of cAMP. Such levels can be regulated by the degradation caused by the phosphodiesterases (PDEs). Therefore, by inhibiting the action of PDEs it is assumed that angiogenesis can be inhibited with the prevention of migration of these cells. The aim of this study was to evaluate the effect PDE inhibitors on angiogenesis in mice by using nonspecific inhibitors (aminophylline) and selective inhibitors of PDE4 (roflumilast) and PDE5 (sildenafil). BALB/c mice were used as a model; under anesthesia, the mice had a sponge of 0.5 x 0.5 cm introduced into their dorsal subcutaneous tissue; they were then divided into 4 groups and daily gavage treated: 1) control group (n=13) – treated with 0.3 mL of saline solution; 2) aminophylline group (n=16) – 50 mg/kg; 3) roflumilast group (n=14) – 5mg/kg; 3) sildenafil group (n=12) –100 mg/kg. After 7 days, with the animals anesthetized, a blood sample was drawn for hemoglobin (Hb) measurement, the sponge implant was removed, and its content was obtained in 2 mL of saline solution for hemoglobin measurement. Absorbance levels (A), the amount of Hb from the sponge (S) and the total blood Hb concentration levels from each mouse were evaluated. According to the results obtained, we concluded that aminophylline, roflumilast and sildenafil (phosphodiesterase inhibitors) did not cause any alteration in the angiogenesis evaluated by the sponge-implantation method.