Resumen Antecedentes: La forma de la arteria coronaria derecha puede variar entre los individuos. Objetivo: El objetivo de este estudio fue investigar si la forma de la arteria coronaria derecha (RCA) tiene algún efecto sobre el conteo de cuadros TIMI (TFC), el puntaje de flujo TIMI y la longitud de distribución de la lesión en pacientes con infarto de miocardio con elevación del ST (STEMI) causado por RCA. Material y métodos: Se incluyeron en el estudio los angiogramas de 163 pacientes que se aplicaron a nuestro hospital con STEMI causado por la arteria coronaria derecha. Se calcularon los TFC. Resultados: Los pacientes se dividieron en dos grupos según la forma geométrica de la arteria coronaria derecha como C (124 puntos, 101 masculino, edad media 66.1 ± 12.3 años) o S (39 puntos, 30 masculino, edad media 60.0 ± 10.8 años) según vista angiográfica desde la posición oblicua izquierda. La ubicación de la lesión fue significativamente mayor en las regiones proximales y medias en comparación con la región distal en pacientes con C-RCA (p < 0.001). TFC fue significativamente mayor en el grupo S-RCA (p = 0.0014). Hubo una diferencia estadísticamente significativa entre los grupos en términos de edad media de (p = 0.003). Conclusión: La frecuencia de las lesiones fue significativamente mayor en las regiones proximales y medias en pacientes con C-RCA. Los TFC fueron significativamente más altos en el grupo S-RCA. Una mayor longitud de S-RCA en comparación con C-RCA y las características locales de tensión de corte también pueden explicar estos hallazgos.

Abstract Background: The shape of the right coronary artery (RCA) may vary between individuals. Objective: The aim of this study was to investigate whether the shape of RCA has any effect on TIMI frame count (TFC), TIMI flow score, and lesion distribution length in patients with ST-elevation myocardial infarction (STEMI) caused by RCA. Materials and methods: The angiograms of 163 patients who applied to our hospital with STEMI caused by the RCA were included in the study. TFC’s were calculated. Results: The patients were divided into two groups according to the geometric shape of the RCA as C (124 pts, 101 males, mean age 66.1 ± 12.3 years) or S (39 pts, 30 males, mean age 60.0 ± 10.8 years) based on the angiographic view from the left oblique position. Lesion location was significantly higher in the proximal and mid regions compared to the distal region in patients with C-RCA (p < 0.001). TFC was significantly higher in the S-RCA group (p = 0.0014). There was a statistically significant difference between the groups in terms of mean age of p = 0.003. Conclusion: Lesion frequency was significantly higher in the proximal and mid regions in patients with C-RCA. TFC’s were significantly higher in the S-RCA group. Longer S-RCA length compared to C-RCA and local shear stress characteristics may also explain these findings.

Fundamento: A ivabradina é um novo agente redutor específico da frequência cardíaca (FC) que melhora a sobrevida livre de eventos de pacientes com insuficiência cardíaca (IC). Objetivo: Avaliar o efeito da ivabradina nos índices temporais da variabilidade da frequência cardíaca (VFC) em pacientes com IC. Métodos: Quarenta e oito pacientes com IC compensada de etiologia não-isquêmica foram incluídos no estudo. O tratamento com ivabradina foi iniciado de acordo com as recomendações mais recentes para a IC. O Holter de 24 horas foi utilizado para analisar os índices da VFC em cada paciente antes e após 8 semanas de tratamento com ivabradina. Resultados: Todos os índices da VFC, o intervalo RR médio, o desvio padrão de todos os intervalos RR normais (DPNN), o desvio padrão de intervalos RR médios de 5 minutos (DPNNM), a média do desvio padrão de todos os intervalos RR normais para todos os segmentos de 5 minutos (índice DPNN), porcentagem de intervalos RR normais sucessivos superiores a 50 milissegundos (pNN50), e a raiz quadrada da média dos quadrados das diferenças entre intervalos RR sucessivos (RMQQD) apresentaram redução no ínicio do estudo, antes do tratamento com ivabradina. Após 8 semanas de tratamento com ivabradina, as médias das FC (83,6 ± 8,0 e 64,6 ± 5,8, p < 0,0001) e todos os índices da VFC, médias dos intervalos RR (713 ± 74 e 943 ± 101 ms, p < 0,0001), DPNN (56,2 ± 15,7 e 87,9 ± 19,4 ms, p < 0,0001), DPNNM (49,5 ± 14,7 e 76,4 ± 19,5 ms, p < 0,0001), índice DPNN (24,7 ± 8,8 e 38,3 ± 13,1 ms, p < 0,0001), pNN50 (2,4 ± 1,6 e 3,2 ± 2,2%, p < 0,0001) e RMQQD (13,5 ± 4,6 e 17,8 ± 5,4 ms , p < 0,0001), foram substancialmente melhorados, e permaneceram nestas condições nos períodos de vigília e sono. Conclusões: Os resultados deste estudo indicam que o tratamento com ivabradina resulta na melhora da VFC em pacientes com IC não isquêmica.

Background: Ivabradine is a novel specific heart rate (HR)-lowering agent that improves event-free survival in patients with heart failure (HF). Objectives: We aimed to evaluate the effect of ivabradine on time domain indices of heart rate variability (HRV) in patients with HF. Methods: Forty-eight patients with compensated HF of nonischemic origin were included. Ivabradine treatment was initiated according to the latest HF guidelines. For HRV analysis, 24-h Holter recording was obtained from each patient before and after 8 weeks of treatment with ivabradine. Results: The mean RR interval, standard deviation of all normal to normal RR intervals (SDNN), the standard deviation of 5-min mean RR intervals (SDANN), the mean of the standard deviation of all normal-to-normal RR intervals for all 5-min segments (SDNN index), the percentage of successive normal RR intervals exceeding 50 ms (pNN50), and the square root of the mean of the squares of the differences between successive normal to normal RR intervals (RMSSD) were low at baseline before treatment with ivabradine. After 8 weeks of treatment with ivabradine, the mean HR (83.6 ± 8.0 and 64.6 ± 5.8, p < 0.0001), mean RR interval (713 ± 74 and 943 ± 101 ms, p < 0.0001), SDNN (56.2 ± 15.7 and 87.9 ± 19.4 ms, p < 0.0001), SDANN (49.5 ± 14.7 and 76.4 ± 19.5 ms, p < 0.0001), SDNN index (24.7 ± 8.8 and 38.3 ± 13.1 ms, p < 0.0001), pNN50 (2.4 ± 1.6 and 3.2 ± 2.2 %, p < 0.0001), and RMSSD (13.5 ± 4.6 and 17.8 ± 5.4 ms, p < 0.0001) substantially improved, which sustained during both when awake and while asleep. Conclusion: Our findings suggest that treatment with ivabradine improves HRV in nonischemic patients with HF.