Avaliação ecocardiográfica da função atrial esquerda: aspectos fisiológicos e clínicos / Echocardiographic evaluation of left atrial function: physiological and clinical aspects / Evaluación Ecocardiográfica de la Función Atrial Izquierda: Aspectos Fisiológicos y Clínicos

A avaliação da função atrial esquerda pode proporcionar informações importantes relacionadas à fisiopatologia de muitas cardiopatias, principalmente quando o envolvimento é das cavidades esquerdas. Entretanto, ao contrário das funções sistólica e diastólica do ventrículo esquerdo, amplamente exploradas em muitas condições clínicas, a função do átrio esquerdo é, ainda, pouco estudada.Conceitos básicos das funções de reservatório, de conduto e de bomba do átrio esquerdo são discutidos, destacando as relações com enchimento ventricular. Métodos de investigação dessas funções são apresentados de forma resumida.

La evaluación de la función atrial izquierda puede proporcionar informaciones importantes relacionadas a la fisiopatología de muchas cardiopatías, principalmente cuando el envolvimiento es de las cavidades izquierdas. Mientras tanto, al contrario de las funciones sistólica y diastólica del ventrículo izquierdo, ampliamente exploradas en muchas condiciones clínicas, la función del atrio izquierdo es, aun, poco estudiada.Conceptos básicos de las funciones de depósito, de conducto y de bomba del atrio izquierdo son discutidos, destacando las relaciones con llenado ventricular. Métodos de investigación de esas funciones son presentados de forma resumida...

The evaluation of left atrial function may provide important information regarding the pathophysiology of many heart diseases, especially when the left chambers are involved. However, as opposed to the left ventricular systolic and diastolic functions, widely exploited in many clinical conditions, the left atrial function is still poorly studied. Basic concepts of the functions of left atrial reservoir, conduit and booster pump are discussed, highlighting the connections with ventricular filling. The methods of investigation of these functions are presented in summary form...

Avaliação ecodopplercardiográfica da função diastólica em cães da raça Boxer / Ecodopplercardiographic evaluation of diastolic function in Boxer dogs

Foram avaliados os principais índices diastólicos, inclusive a velocidade de propagação mitral (Vp), em 36 cães sadios da raça Boxer, 18 de cada sexo, de idade entre um ano e meio e seis anos. A relação raiz aórtica e átrio esquerdo medida no modo B foi de 1,17±0,11. Os picos de velocidades das ondas de enchimento atrial esquerdo foram: sistólica 31,41±6,87cm/s, diastólica (D) 73,85±17,04cm/s e de reversão atrial 28,90±8,33cm/s. A relação das ondas de enchimento ventricular inicial (E) e atrial (A) foi 1,58±0,19 na valva mitral e de 1,62±0,29 na valva tricúspide. Entre os índices avaliados, a Vp só se correlacionou fracamente (r=0,39) com as ondas E e A mitrais e com a onda D, mostrando-se um índice, relativamente, independente. A Vp não apresentou diferença significativa entre os sexos nem entre examinadores. A Vp diminuiu com o aumento da idade e exibiu valor médio, neste estudo, de 99,73±16,06cm/s

Major diastolics indexes, including the mitral propagation velocity (Vp), were evaluated in 36 healthy Boxer dogs, 18 males and 18 females, aging from 1.5 to 6-years-old. The aortic root and left atrium ratio, measured in B mode, was 1.17±0.11. The peaks of velocity of waves of the left atrium filling were: systolic 31.41±6.87cm/s, diastolic 73.85±17.04cm/s and atrial reversal 28.90±8.33cm/s. The ratios of the waves of initial ventricular filling were 1.58±0.19 to mitral valve and 1.62±0.29 to tricuspid valve. From the evaluated indexes, the Vp was only weakly correlated (r=0.39) with E and A waves of mitral valve and with D, showing itself, relativity, as an independence index. Regarding to the Vp, no significant differences were seen between the gender of the animals and among the observers. The Vp decreased as the age increased, showing mean values of 99.73±16.06cm/s

Anatomia funcional da junção entre o átrio esquerdo e as veias pulmonares / Functional Anatomy of the Junction Between the Left Atrium and The Pulmonary Veins

PURPOSE--To study the spatial arrangement of the bundles of myocardial fibers presents in the left atrial-venous junctions and in the wall of the pulmonary veins. METHODS--The study was made on 24 human adult hearts, together with pulmonary vessels, fixed in 10 per cent formaldehyde solution. Each specimen was cleared of remnants of pericardium to expose the myocardial fibers as clearly as possible. Particular attention was paid to the atrial-venous junction and the extension of the myocardial fibers in the pulmonary veins. The specimens were embedded in celloidin and cut serially at a thickness of 70 mu and stained by methods of Azan's trichrome. RESULTS--The myocardial bundles leave the atrial wall around the openings of all pulmonary veins forming a sphincter-like structure. These fibers are continuous in the adventitial coat running in oblique or spiral directions. Some bundles, more external, leaving from the atrial wall, surround the ostium of the veins and return to the atrium, forming true loops. CONCLUSION--The extremities of the pulmonary veins and their junctions with the atrium have a morphological substract which may be of physiological importance in the control of the pulmonary venous pressure and blood flow