Right ventricular involvement in anterior myocardial infarction: a tissue Doppler-derived strain and strain rate study

OBJECTIVE: Strain and strain rate imaging is currently the most popular echocardiographic technique that reveals subclinical myocardial damage. There are currently no available data on this imaging method with regard to assessing right ventricular involvement in anterior myocardial infarction. Therefore, we aimed to evaluate right ventricular regional functions using a derived strain and strain rate imaging tissue Doppler method in patients who were successfully treated for their first anterior myocardial infarction. METHODS: The patient group was composed of 44 patients who had experienced their first anterior myocardial infarction and had undergone successful percutaneous coronary intervention. Twenty patients were selected for the control group. The right ventricular myocardial samplings were performed in three regions: the basal, mid, and apical segments of the lateral wall. The individual myocardial velocity, strain, and strain rate values of each basal, mid, and apical segment were obtained. RESULTS: The right ventricular myocardial velocities of the patient group were significantly decreased with respect to all three velocities in the control group. The strain and strain rate values of the right mid and apical ventricular segments in the patient group were significantly lower than those of the control group (excluding the right ventricular basal strain and strain rate). In addition, changes in the right ventricular mean strain and strain rate values were significant. CONCLUSION: Right ventricular involvement following anterior myocardial infarction can be assessed using tissue Doppler based strain and strain rate .

Efectos del entrenamiento físico de larga duración sobre la función y remodelación del ventrículo izquierdo en pacientes con infarto miocárdico de pared anterior / Effects of long-term exercise training on left ventricular function and remodeling in patients with anterior wall myocardial infarction

Objetivo: Determinar los efectos del entrenamiento físico prolongado sobre la función y remodelación del ventrículo izquierdo después del infarto miocárdico. Métodos: Fueron estudiados 90 pacientes con un primer infarto miocárdico agudo, de localización anterior; todos recibieron el tratamiento médico convencional. Se realizaron pruebas de esfuerzo máximas, ecocardiogramas y ventriculografías isotópicas en reposo y esfuerzo a los 2, 6 y 12 meses de evolución; el seguimiento clínico medio fue de 36.3 ± 17 meses. A todos se les incorporó a un programa de rehabilitación cardíaca con entrenamiento físico moderado o intenso, durante un año como mínimo. Un 41.1% tuvieron una disfunción severa del ventrículo izquierdo. Resultados: Todos los parámetros ergométricos que expresaron capacidad funcional incrementaron significativamente en la evaluación del sexto mes (p < 0.0005), permaneciendo invariables al año. Se comprobó una disminución significativa (p < 0.01) de isquemia miocárdica al esfuerzo a los 6 meses. Las variables que midieron tamaño y función del ventrículo izquierdo no se modificaron evolutivamente. La mortalidad total de la serie fue un 13.3%, de causa cardiovascular un 8.9% y la morbilidad un 16.7%. Conclusiones: El entrenamiento físico prolongado no mostró efectos deletéreos sobre la función y remodelación del ventrículo izquierdo y se obtuvieron efectos funcionales y clínicos beneficiosos en estos pacientes infartados rehabilitados.

Objective: To assess the effects of long-term exercise training on the function and remodeling of the left ventricle after myocardial infarction. Methods: We studied 90 patients with a first acute anterior-wall myocardial infarction, all received conventional medical treatment. Symptom-limited maximal exercise stress tests, echocardiograms and effort-rest isotopic ventriculographies at 2, 6 and 12 months after myocardial infarction were performed; the follow-up time averaged 36.3 ± 17 months. All patients joined a cardiac rehabilitation program with moderate or intense exercise training lasting at least a year. Of all patients, 41.1% suffered severe left ventricle dysfunction. Results: Ergometric parameters that expressed functional capacity increased significantly (P< .0005) at the sixth month evaluation and remained unchanged after a year. There was significant decrease (P< .01) of exercise myocardial ischemia at 6 months. The variables that measured size and function of left ventricle did not change during evolution. Morbidity amounted to 16.7% and total mortality of the series was 13.3%, with 8.9% of cardiovascular cause. Conclusions: Long-term exercise training showed no deleterious effects on left ventricle function or remodeling and beneficial functional and clinical effects were obtained in these rehabilitated postinfarction patients.

Impacto do padrão geométrico ventricular na remodelação cardíaca após o infarto do miocárdio / Impact of ventricular geometric pattern on cardiac remodeling after myocardial infarction

FUNDAMENTO: A relevância do padrão de geometria após o infarto do miocárdio não é conhecida. OBJETIVOS: Analisar a presença de diferentes padrões de geometria ventricular esquerda (VE) e seu impacto como preditor de remodelação em pacientes com infarto do miocárdio. MÉTODOS: Pacientes com infarto agudo anterior (n = 80) foram divididos de acordo com o padrão de geometria: normal (índice de massa [IMVE] normal e espessura relativa da parede [ERP] normal), remodelação concêntrica (IMVE normal e ERP aumentada), hipertrofia concêntrica (IMVE e ERP aumentadas) e hipertrofia excêntrica (IMVE aumentado e ERP normal). Após seis meses, foi repetido o ecocardiograma. RESULTADOS: Quatro pacientes foram a óbito. Dos sobreviventes, 41 apresentaram remodelação (R+), enquanto 39 não remodelaram (R-). Considerando-se o padrão geométrico, houve a seguinte distribuição: 24 pacientes com padrão normal, 13 com remodelação concêntrica, 29 com hipertrofia concêntrica e 14 com hipertrofia excêntrica. Os pacientes que remodelaram apresentaram maiores tamanhos de infarto analisados pelo pico da CPK (R+ = 4.610 (1.688 - 7.970), R- = 1.442 (775 - 4.247), p < 0,001) e da CK-MB (R+ = 441 (246 - 666), R- = 183 (101 - 465), p < 0,001), tendência a maior prevalência de remodelação concêntrica (R+ = 10, R- = 3, p = 0,08) e menor prevalência de hipertrofia excêntrica (R+ = 2, R- = 12, p = 0,006). Na análise de regressão multivariada, o tamanho do infarto foi preditor (OR = 1,01; p = 0,020) e a hipertrofia excêntrica foi fator protetor (OR = 0,189; p = 0,046) de remodelação ventricular após a oclusão coronariana. CONCLUSÃO: O padrão de geometria ventricular pode ter impacto no processo de remodelação em pacientes com infarto do miocárdio.

BACKGROUND: The relevance of left ventricular (LV) geometric pattern after myocardial infarction is not known. OBJECTIVES: To analyze the presence of different LV geometric patterns and teir impact as a predictor of remodeling in patients with myocardial infarction. METHODS: Patients with anterior acute myocardial infarction (n = 80) were divided according to the geometric pattern: normal (normal left ventricular mass index [LVMI] and normal relative wall thickness [RWT]), concentric remodeling (normal LVMI and increased RWT), concentric hypertrophy (increased LVMI and RWT) and eccentric hypertrophy (increased LVMI and normal RWT). After six months, echocardiographic assessment was repeated. RESULTS: Four patients died. Of the survivors, 41 showed remodeling (R +), whereas 39 did not (R-). Considering the geometric pattern, the cases were distributed as follows: 24 patients with normal pattern, 13 with concentric remodeling, 29 with concentric hypertrophy and 14 with eccentric hypertrophy. Patients who showed remodeling had larger infarction sizes analyzed by peak CPK (R + = 4,610 (1,688-7,970), R- = 1,442 (775-4247), p <0.001) and CK-MB (R + = 441 (246 - 666), R- = 183 (101-465), p <0.001), trend towards higher prevalence of concentric remodeling (R+ = 10, R- = 3, p = 0.08) and lower prevalence of eccentric hypertrophy (R + = 2 R- = 12, p = 0.006). In the multivariate regression analysis, infarction size was a predictor (OR = 1.01, p = 0.020) and eccentric hypertrophy was a protective factor (OR = 0.189, p = 0.046) of ventricular remodeling after coronary occlusion. CONCLUSION: The LV geometric pattern of can have an impact on the remodeling process in patients with myocardial infarction.

Index of Microcirculatory Resistance as Predictor for Microvascular Functional Recovery in Patients with Anterior Myocardial Infarction

IMR is useful for assessing the microvascular dysfunction after primary percutaneous coronary intervention (PCI). It remains unknown whether index of microcirculatory resistance (IMR) reflects the functional outcome in patients with anterior myocardial infarction (AMI) with or without microvascular obstruction (MO).This study was performed to evaluate the clinical value of the IMR for assessing myocardial injury and predicting microvascular functional recovery in patients with AMI undergoing primary PCI. We enrolled 34 patients with first anterior AMI. After successful primary PCI, the mean distal coronary artery pressure (Pa), coronary wedge pressure (Pcw), mean aortic pressure (Pa), mean transit time (Tmn), and IMR (Pd * hyperemic Tmn) were measured. The presence and extent of MO were measured using cardiac magnetic resonance image (MRI). All patients underwent follow-up echocardiography after 6 months. We divided the patients into two groups according to the existence of MO (present; n = 16, absent; n = 18) on MRI. The extent of MO correlated with IMR (r = 0.754; P < 0.001), Pcw (r = 0.404; P = 0.031), and Pcw/Pd of infarct-related arteries (r = 0.502; P = 0.016). The IMR was significantly correlated with the DeltaRegional wall motion score index (r = -0.61, P < 0.01) and DeltaLeft ventricular ejection fraction (r = -0.52, P < 0.01), implying a higher IMR is associated with worse functional improvement. Therefore, Intracoronary wedge pressures and IMR, as parameters for specific and quantitative assessment of coronary microvascular dysfunction, are reliable on-site predictors of short-term myocardial viability and Left ventricle functional recovery in patients undergoing primary PCI for AMI.