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Objective: Understanding cardiac anatomy is the key to solve unknown issues about its function. The continuous and helical myocardial structure plays a fundamental role in its torsion-detorsion motions. Does the apex, a constitutive part of the ventricle, have relevance in cardiac dynamics or is it simply a cul-de-sac? The aim of this study was to answer this question. Methods: Four young bovine and four human hearts (two embryos and two adults) were used for the anatomo-histological studies. Two procedures were carried out for this investigation: a) the continuous myocardium unfolding to observe the fiber arrangement at the tip of the left ventricle, called the apical zone; and b) horizontal and longitudinal sections to study the structure of the apex. The horizontal sections were performed between the middle 2/3 and the apex, and the longitudinal ones, sectioning left ventricular apex, with an apex-base orientation. Results: In all the human and bovine hearts studied we found that the apex corresponds only to the left ventricle, where the twist of the descending segment is located, in the ascending continuity of the myocardium. The apical cul-de-sac has practically no muscular plane at its end. It is internally lined by the endocardium and externally by the epicardium. The muscular plane has only 10% thickness of the adjacent myocardium, a structural concept confirmed by transillumination. Conclusions: The apex is a cul-de-sac practically devoid of muscle, in which the endocardium and epicardium are attached, but which performs the functions of supporting intraventricular pressures and being a constitutive part of the torsion and de torsion motions

Background: Understanding cardiac anatomy is the key to solve unknown issues about its function. The continuous and helical myocardial structure plays a fundamental role in its torsion-detorsion motions. Does the apex, a constitutive part of the ventricle, have relevance in cardiac dynamics or is it simply a cul-de-sac? The aim of this study was to answer this question. Methods. Four young bovine and four human hearts (two embryos and two adults) were used for the anatomo-histological studies. Two procedures were carried out for this investigation: a) the continuous myocardium unfolding to observe the fiber arrangement at the tip of the left ventricle, called the apical zone; and b) horizontal and longitudinal sections to study the structure of the apex. The horizontal sections were performed between the middle 2/3 and the apex, and the longitudinal ones, sectioning left ventricular apex, with an apex-base orientation. Results. In all the human and bovine hearts studied we found that the apex corresponds only to the left ventricle, where the twist of the descending segment is located, in the ascending continuity of the myocardium. The apical cul-de-sac has practically no muscular plane at its end. It is internally lined by the endocardium and externally by the epicardium. The muscular plane has only 10% thickness of the adjacent myocardium, a structural concept confirmed by transillumination. Conclusions. The apex is a cul-de-sac practically devoid of muscle, in which the endocardium and epicardium are attached, but which performs the functions of supporting intraventricular pressures and being a constitutive part of the torsion and detorsion motions

Resumen: La pérdida de la geometría ventricular es la principal causa de progresión de la insuficiencia cardiaca y de riesgo en la morbimortalidad en pacientes con cardiomiopatía dilatada. La insuficiencia mitral ocurre secundariamente a la dilatación anular, a la geometría ventricular izquierda alterada y a la disfunción del músculo papilar. La cirugía de restauración ventricular (CRV) se introdujo como una opción terapéutica con la hipótesis que mejora el funcionamiento mitral al reducir los volúmenes del ventrículo izquierdo, las distancias de los músculos papilares y restaurar la geometría cardiaca. Este trabajo presenta el caso clínico de una paciente con insuficiencia cardiaca de etiología isquémica necrótica, que fue intervenida quirúrgicamente y se le realizó restauración ventricular, células madre y matriz de colágeno biodegradable. En el seguimiento a los dos años, la paciente no necesito más ingresos por descompensación, se observó que la clase funcional (CF) (NYHA) mejoró de CF III a I. La fracción de eyección del ventrículo izquierdo (FEVI) se incrementó de 20 a 27%, la insuficiencia mitral se redujo de grado IV a II, presentando estudios complementarios con mejora en el ejercicio. Los resultados de este caso sugieren que la técnica de restauración ventricular basada en el modelo de la banda miocárdica se aproxima a la anatomía y fisiología cardiaca normal, corrigiendo la insuficiencia mitral isquémica sin asociar cirugía valvular. Abstract: Loss of ventricular geometry is the main cause of progression of heart failure and risk of mortality in patients with dilated cardiomyopathies. Mitral regurgitation occurs secondary to annular dilatation, altered left ventricular geometry and papillary muscle dysfunction. Ventricular restoration surgery was introduced as a therapeutic option with the hypothesis that improves mitral functioning by reducing left ventricular volumes, papillary muscle distances and restoring cardiac geometry. This work presents a clinical case of a patient with heart failure of necrotic ischemic etiology, who underwent surgery and had ventricular restoration, stem cells and biodegradable collagen matrix. At the two-year follow-up, the patient did not need further hospitalizations due to decompensation, it was observed that the functional class (NYHA) improved from FC III to I. On the other hand, the ejection fraction improved from 20% to 27%, Mitral Insufficiency was reduced from grade IV to grade II presenting complementary studies with improvement in exercise. The results of this case suggest that the miocardial band and the restoration technique based on this model approximate normal cardiac anatomy and physiology, correcting ischemic mitral regurgitation without associating valvular surgery.