Archivos del Instituto de Cardiologia de Mexico最新文献

Three pregnant women with 5 +/- 1.7 weeks of pregnancy and mitral stenosis are described. Their valve area were < 1.0 cm2. They received medical treatment with little improvement and were included in our valvotomy percutaneous mitral (VPM) program with Inoue technique before their 30th week of pregnancy. Before they were treated with low molecular weight heparin (LMWH), Enoxiparin) as prophylaxis of intracavitary thrombus formation transthoracic and transesophageal echocardiogram demonstrated the absence of thrombus. We used 40 mgs. subcutaneous injection once a day during 16 weeks. Repeated transthoracic and transesophageal echocardiogram during VPM showed no evidence of intracavitary thrombus. Complete blood count and coagulation parameters remained within normal limits. The three cases delivered a healthy products. In conclusion, although this series is small, we show that the LMWH can be used in the first trimester of pregnancy as prophylactic treatment instead of oral anticoagulant treatment.

Cases of familial preexcitation syndrome represent a specific subgroup of patients that may result from diverse mechanisms: failure in development and genetic predisposition are the main mechanism involved. We determined the prevalence of this syndrome in first degree relatives of patients with proved accessory pathways by electrophysiologic study and compared such prevalence with the general population (0.15%). In five out of 469 patients (1.06%) we found an accessory pathway in one or more member of their family. Only 6 out of 3752 had preexcitation (0.15%); this prevalence was similar to the general population (P = NS). The identification of family members with this syndrome may be incomplete because we only chose for the study symptomatic patients. We did not observed multiple pathways and in one case we found atrial septal defect. Our data demonstrated familial preexcitation in five families suggesting hereditary predisposition.

Deep venus thrombosis may result in pulmonary embolism. In rare instances, embolization has occurred, not directly to the pulmonary arterial tree, but to the right heart chambers. Although the value of echocardiography in the diagnosis is well recognised, their is no consensus for the appropriate treatment. We report herein six cases of floating right atrial thrombi, diagnosed by echocardiography, in patients with pulmonary embolism, or unexplained shock or syncope. Surgical embolectomy was carried out in 4 patients, and thrombolytic therapy in 2, without in-hospital mortality. The high mortality associated to this entity may be improved by rapid echocardiographic recognition and emergency treatment with thrombolysis or surgery. Our data suggest the possible use of thrombolysis as a first-choice therapy in selected patients.

The purpose of this study was to assess the clinical and echocardiographic characteristics of constrictive pericarditis (CP) and restrictive cardiomyopathy (RC) and to compare them with the results obtained with cardiac catheterization. Clinical history, electrocardiogram and X-ray were taken in all patients, and transthoracic and transesophageal echocardiography were performed. Cardiac catheterization with transmyocardial biopsy was performed on only 5 patients. Wall thickness and left ventricular dimensions were normal in all patients with CP. Wall thickness was increased in those with RC. No patients demonstrated alterations in segmental wall movement. The pericardium was thickened and abnormally bright in the 3 patients with CP. In patients with CP the percentage of atrioventricular, semilunar, pulmonary and hepatic flow changes with respiration were more than 10%. In patients with RC this flow variation was less notable. However, the percentage of systolic and diastolic flow velocity increase of hepatic veins during expiration was greater than in CP. We can conclude that M-mode, two dimensional and Doppler echocardiography is extremely useful noninvasive method to differentiate CP and RC with good correlation with cardiac catheterization.

This study describes the natural history and evolution of 67 patients with congenital auriculoventricular heart block admitted in the Instituto Nacional de Cardiología "Ignacio Chávez", Mexico, D.F. from 1944 to 1998. There were 35 (52%) females and 32 (47%) males, with mean follow up period of 93.7 +/- 104 months. Most of the patients were without structural cardiovascular disease (90%). The most frequent symptoms were dyspnea and syncope. Electrocardiograms showed a ventricular heart rate of 42.2 +/- 9 beats/minute. 85.7% of patients had a supra-Hisian complete heart block. In 31% of patients a pacemaker was implanted because syncope. Overall mortality was 4.4% and malignant ventricular arrhythmias were the principal contributors. Risk factors for mortality identified in this study were junctional escape rhythm lower than 50 beats/minute, inappropriate chronotropic response during exercise, R-R interval prolongation at night, enlargement of cardiac chambers, depressed left ventricular ejection fraction and prolonged QT interval. In all of these conditions we recommend permanent pacemaker implantation.

Unlabelled: Alveolar hypoxia is the most powerful pulmonary vasoconstrictor. In a previous work, we did not demonstrate significant changes in vascular reactivity and edema formation in an isolated canine lobe model during alveolar hypoxia. The purpose of this study is to define vascular pulmonary reactivity and edema formation after induction of pulmonary vasoconstriction using a prostaglandin inhibitor like tiaprofenic acid and alveolar hypoxia. Six isolated canine pulmonary lobules were instrumented and studied, all of them under two conditions (normoxia FIO2 21% and hypoxia FIO2 5%) four starting in normoxia condition and 2 starting in hypoxia condition.

Results: No significant changes in filtration rate were found, normoxia 0.42 +/- 0.41, hypoxia 0.37 +/- 0.51 ml/min/100 g pulmonary tissue P = NS. The arterial pressure in basal conditions was 25.1 +/- 6.21, and during hypoxia increased to 37 +/- 7.19 cm H2O (Delta 12.0 +/- 1.2 cm H2O). P < 0.001.

Conclusion: Hypoxia vascular reactivity was significantly increased in tiaprofenic acid pretreated isolated canine lobes, no changes in pulmonary permeability was found nor increased rate in edema formation.

We studied the therapeutic effect of standard heparin (HS) compared with low-molecular-weight (HBPM) in two homogeneous groups of 14 patients heparin selected at random, with clinical history and electrocardiographic signs of unstable angina pectoris. Patients received the conventional treatment with platelets' inhibitors, nitrates, adrenergic beta-blockers or calcium antagonists. Both heparins, separately, showed statistical therapeutic effect on the symptoms and signs of unstable angina pectoris. They decreased to zero the number and duration of symptomatic myocardial ischemic events observed by ambulatory electrocardiogram (EKG-Holter). The symptoms of the angina pectoris disappeared at the same elapsed time: in 51.9 +/- 20.2 min. for the HS, and in 48.14 +/- 20.7 min. for the HBPM. They decreased the frequency of the silent myocardial ischemia observed at the EKG-Holter: 9 events decreased to 4 with the HS, and 8 events decreased to 3 with the HBPM. They decreased the total elapsed time of the silent ischemia from 52 min. to 15 min., and the mean elapsed time of the silent ischemia decreased from 3.71 +/- 3.29 min. to 1.07 +/- 1.81 min. with the HS (P < 0.001). With HBPM it decreased the total elapsed time of the silent ischemia from 60 min to 10 min, and the mean elapsed time of the silent ischemia decreased from 4.28 +/- 4.49 min. to 0.71 +/- 1.43 min. (P < 0.02). Both heparins considerably decreased the frequency of the lethal arrhythmias. Although in this study we did not find statistical differences in the therapeutic action of either heparins, HBPM reduced rapidly angina symptoms and the events associated to angina pectoris, cardiac arrhythmias, specially lethal extrasystolia, conduction defects and atrial paroxysmal tachycardia. Compared to HS, HBPM is easily applied, does not produce side effects on coagulation or bleeding time.