Coronary flow reserve in sickle cell anemia.

BACKGROUND: Patients with sickle cell anemia (SCA) frequently present with episodes of chest pain, alterations in the resting electrocardiogram, and changes in cardiac structure and functions. OBJECTIVE: To evaluate the effect of recurrent episodes of vaso-occlusion on the coronary microcirculation. METHODS: Coronary flow velocity and coronary flow reserve (CFR) of stable patients with SCA (n=10, 5 females, 24.4+/-5.4 years) were measured in the anterior descending coronary artery with transesophageal echocardiogram at baseline and after intravenous adenosine-induced maximum hyperemia, and compared to those of patients with sickle cell trait (TRA, n=10, 5 females, 27.7+/-3.2 years), iron deficiency anemia (IRO, n=8, 8 females, 26.6+/-5.2 years) and control group (NOR, n=10, 5 females, 26.3+/-6.3 years). RESULTS: The SCA group presented increased diastolic coronary flow velocities (p<0.01) at baseline and during maximum hyperemia (67.3+/-14.0 and 198.2+/-37.9 cm/s, respectively) when compared with the other three groups - TRA (34.4+/-11.9 and 114.7+/-36.4 cm/s), IRO (42.4+/-10.4 and 141.0+/-18.7 cm/s) and NOR (38.1+/-10.0 and 126.8+/-24.6 cm/s). However, CFR was normal in the SCA group (3.0+/-0.7) and comparable (p=0.70) to the other groups - TRA (3.4+/-0.8), IRO (3.5+/-1.2), and NOR (3.4+/-0.8). CONCLUSION: Despite the higher coronary flow velocities already observed at baseline and also during maximum hyperemia, CFR is normal in SCA, which suggests preserved coronary microcirculation. The episodes of vaso-occlusion are not responsible for the cardiologic findings in this disease.

Reserva de fluxo coronariano na anemia falciforme / Coronary flow reserve in sickle cell anemia

FUNDAMENTO: Pacientes com anemia falciforme (FAL) apresentam freqüentemente episódios de dor precordial, possuem alterações eletrocardiográficas em repouso e exibem alterações da estrutura e das funções cardíacas. OBJETIVO: Avaliar o efeito dos episódios repetitivos de vaso-oclusão sobre a microcirculação coronariana. MÉTODOS: Pacientes estáveis com FAL (n = 10, cinco mulheres, 24,4 + 5,4 anos) foram submetidos a medida das velocidades de fluxo coronariano e da reserva de fluxo coronariano (RFC) na artéria coronária descendente anterior por meio de ecocardiografia transesofágica em estado basal e após hiperemia máxima, obtida com adenosina intravenosa. Esses pacientes foram comparados a pacientes com traço falciforme (TRA, n = 10, cinco mulheres, 27,7 + 3,2 anos), anemia ferropriva (FER, n = 8, oito mulheres, 26,6 + 5,2 anos) e grupo controle (NOR, n = 10, cinco mulheres, 26,3 + 6,3 anos). RESULTADOS: O grupo FAL apresentou aumento das velocidades de fluxo coronariano diastólico (p < 0,01) em estado basal e durante hiperemia máxima (67,3 + 14,0 cm/s e 198,2 + 37,9 cm/s, respectivamente), quando comparado aos três outros grupos (TRA, 34,4 + 11,9 cm/s e 114,7 + 36,4 cm/s; FER, 42,4 + 10,4 cm/s e 141,0 + 18,7 cm/s e NOR, 38,1 + 10,0 cm/s e 126,8 + 24,6 cm/s). Entretanto, a RFC foi normal no grupo FAL (3,0 + 0,7) e comparável (p = 0,70) aos demais grupos (TRA, 3,4 + 0,8; FER, 3,5 + 1,2 e NOR, 3,4 + 0,8). CONCLUSÃO: Apesar de maiores velocidades de fluxo coronariano já em estado basal e também durante hiperemia máxima, a RFC é normal na FAL, o que sugere integridade da microcirculação coronariana. Os episódios de vaso-oclusão não são responsáveis pelos achados cardiológicos da doença.

BACKGROUND: Patients with sickle cell anemia (SCA) frequently present with episodes of chest pain, alterations in the resting electrocardiogram, and changes in cardiac structure and functions. OBJECTIVE: To evaluate the effect of recurrent episodes of vaso-occlusion on the coronary microcirculation. METHODS: Coronary flow velocity and coronary flow reserve (CFR) of stable patients with SCA (n=10, 5 females, 24.4±5.4 years) were measured in the anterior descending coronary artery with transesophageal echocardiogram at baseline and after intravenous adenosine-induced maximum hyperemia, and compared to those of patients with sickle cell trait (TRA, n=10, 5 females, 27.7±3.2 years), iron deficiency anemia (IRO, n=8, 8 females, 26.6±5.2 years) and control group (NOR, n=10, 5 females, 26.3±6.3 years). RESULTS: The SCA group presented increased diastolic coronary flow velocities (p<0.01) at baseline and during maximum hyperemia (67.3±14.0 and 198.2±37.9 cm/s, respectively) when compared with the other three groups - TRA (34.4±11.9 and 114.7±36.4 cm/s), IRO (42.4±10.4 and 141.0±18.7 cm/s) and NOR (38.1±10.0 and 126.8±24.6 cm/s). However, CFR was normal in the SCA group (3.0±0.7) and comparable (p=0.70) to the other groups - TRA (3.4±0.8), IRO (3.5±1.2), and NOR (3.4±0.8). CONCLUSION: Despite the higher coronary flow velocities already observed at baseline and also during maximum hyperemia, CFR is normal in SCA, which suggests preserved coronary microcirculation. The episodes of vaso-occlusion are not responsible for the cardiologic findings in this disease.

Effect of Losartan on left ventricular diastolic function in patients with nonobstructive hypertrophic cardiomyopathy.

In hypertrophic cardiomyopathy (HC), diastolic dysfunction of the left ventricle is a prominent feature caused by myocardial hypertrophy and fibrosis. Angiotensin II has trophic and profibrotic effects on the heart, and the blockade of angiotensin II receptors reverses hypertrophy and fibrosis in human cardiac diseases and in animal HC. This study investigated the short-term (6 months) effects of losartan 100 mg/day in 20 patients with nonobstructive HC, with an emphasis on left ventricular (LV) diastolic dysfunction, compared with 10 patients with HC who were not treated. At the final evaluation, significant changes were observed in the losartan group: a left atrial diameter decrease (p<0.0001), a tissue Doppler early (Ea) mitral annulus diastolic velocity increase (p=0.003) and an E/Ea ratio decrease (p=0.0002), and a significant decrease in plasma levels of the aminoterminal fragment of pro-brain natriuretic peptide (NT-pro-BNP) from a median of 860 to 606 pg/ml (p=0.001). A significant correlation was found between percentage changes in NT-pro-BNP and the E/Ea ratio from baseline to 6 months (r=0.61, p=0.002). In the 2 groups, echocardiographic LV wall and cavity measures did not change. In conclusion, in selected patients with nonobstructive HC, losartan during a 6-month period improved LV diastolic function.