[Doppler echocardiography assessment of tricuspid valve prosthesis with normal function and with dysfunction due to obstruction]. / Evaluación mediante ecocardiografía Doppler de las prótesis valvulares tricuspídeas con función normal y con disfunción por obstrucción.

UNLABELLED: In order to know the normal ranges of the maximum velocity and the pressure half-time between normal functioning tricuspid prostheses and malfunctioning tricuspid prostheses due to obstruction, we studied 25 patients with tricuspid prostheses (11 mechanical and 14 biological); they were divided in 2 groups: group I: 14 patients without clinical evidence of malfunction and; group II: 11 patients with malfunction due to obstruction confirmed by catheterization, surgery and/or necropsy. The peak gradient was estimated by the modified Bernoulli equation and the prosthetic valve area by the pressure halftime method. RESULTS: the mean peak velocity in group I was 147 +/- 18 cm/sec versus 165 +/- 16 cm/sec (p NS) in group II. The mean pressure half-time in group I was 124 +/- 20 msec versus 355 +/- 48 msec (p less than 0.001) in group II. CONCLUSIONS: 1. A pressure half-time greater than 200 msec is very suggestive of malfunction due to obstruction (p less than 0.001). 2. There are normo-functioning tricuspid prostheses with prolonged pressure half-time, and the values that divides these groups from those with malfunction is small: 199 and 244 msec, that is why we suggest that every patient has to have his her own echocardiographic control in the immediate postoperative period.

[Silent myocardial ischemia: a problem in diagnosis and treatment]. / Isquemia miocárdica silenciosa: un problema de diagnóstico y tratamiento.

We tried to establish the incidence of silent myocardial ischemia (SMI) in the general population and also in patients with recognised ischemic heart disease. For this, purpose 2, 375 stress tests (ST) with Bruce protocol were reviewed, 364 were positive and those patients were divided in two groups: group I with SMI during the ST and group II with myocardial ischemia and angina during the ST. Coronary risk factors ergometric behaviour and angiographic factors were analysed. Group I had 263 patients with SMI (71%). Group II had 111 patients with ischemia and angina (29%) P less than 0.05; 90 patients had diabetes mellitus in group I and 19 in group II P less than 0.05. A previous myocardial infarction was registered in 157 patients from group I and 55 from group II P less than 0.05. The remaining coronary risks factors, ergometrics variables and significance and number of diseased coronary vessels were similar in both groups. We conclude that SMI is a frequent event in patients with ischemic heart disease. It represents probably the most frequent event in this disease. Previous myocardial infarction and diabetes mellitus may play an important role in the pathogenesis of SMI. The ST and Holter monitoring are dependable procedures for the identification of SMI and should be always performed specially in patients with high coronary risk factors. Once detecting SMI a therapeutic plan should be considered for medical, angioplastic or surgical procedures even in asymptomatic patients.

Contribucion del fonomecanocardiograma y el ecocardiograma al estudio del paciente con valvulopatia mitral reumatica. / The phonomecanocardiography and the echocardiography in the study of patient with rheumatic mitral valvulopathy

Se estudiaron 39 pacientes enviados al Servicio de Gabinetes del Hospital de Cardiologia y Neumologia del IMSS, con diagnosticos clinico de lesion valvular mitral reumatica; de ellos 28 (7.8 por ciento), fueron del sexo femenino, y 12 (28.2 por ciento), del masculino. El rango de edad fue de 20 a 65 anos (media de 40.1). Todos los pacientes fueron operados, confirmandose la afeccion mitral. Se confrontaron los diagnosticos clinicos, fonomecanocardiografico, ecocardiografico y quirurgico contando con la informacion proporcionada por el FMCG y el ECO con el diagnostico de cirugia. Las lesiones se dividieron en dos tipos: EMP y DLM. Se hizo el analisis de sensibilidad y especificidad segun cada pocedimiento diagnostico. El FMCG, mostro su mayor aportacion para el diagnostico de la EMP. Tanto en la DLM como en la EMP al contar con la informacion de FMCG y ECO, el clinico mejora sus indices. Se estudio tambien el valor productivo del clinico y del ECO en cuanto a la presencia de calcio valvular mitral. El ECO mostro ventajas sobre el clinico para la identificacion del calcio valvular (90 por ciento de sensibilidad especificidad para el ECO, comparados com 9.9 y 50 por ciento respectivamente del clinico). Se pone de relieve la utilidad de los estudios no invasores de FMCG y ECO, como procedimientos preoperatorios sistematicos para el enfermo con cardiopatia mitral reumatica

[Phonomechanocardiographic analysis in patients with artifical pacemaker]. / Análisis fonomecanocardiográfico en pacientes con marcapaso artificial

Eighteen patients with artificial pacemakers have been studied by phonomecanocardiographic means. All had complete atrio-ventricular block. Ten had an endocardial electrode in the right ventricle and 10 an epicardial in the free wall of the left ventricle. Two patients were studied, first with a temporal endocardial pacemaker and then with a permanent one. The studies were divided in 3 groups: Group I. In six cases comparison was made between the systolic tunes of the normally conducted cycles, and the ones produced by direct ventricular stimulations. The beats produced by direct ventricular stimulation showed a statistically significant diminution of the function of the left ventricle. This was reflected by a shorter relative ejection period. This diminution can possibly be explained by one of two mechanisms: absence of the "atrial kick", or alteration in the sequence of depolarization and ventricular contraction, producing an asynchrony in the contraction. This would lead us to suppose that the best site for contact of the electrode would be the middle third of the left aspect of the ventricular septum, where the activation starts normally. Group II. Ventricular function was compared in 20 cases, depending on the site of electrical stimulation: endocardium of right ventricle or epicardium of the left ventricle: there were no statistically significant differences. Group III. On 14 cases we studied cycles in which an effective contribution of the atrial kick could be expected, because the interval between the P wave and the electrical artifact was less than 300 msec. These were compared with others with a larger, statistically significant, improvement of the left ventricular function it was observed as a longer ejection period in the cases with a P wave-electrical artifact pause shorter than 300 msec.