[Coronary disease and noncardiac surgery. An evaluation of the surgical risk]. / Doença coronária e cirurgia não cardíaca. Avaliação do risco cirúrgico.

Coronary artery disease is one of the leading causes of death in developed countries and one of the factors contributing to high mortality associated with noncardiac surgical procedures. This is the reason why is so important to correctly assess surgical risk in patients with ischemic heart disease. These patients can be evaluated by a simple clinic examination, electrocardiogram and chest X-ray. In asymptomatic patients or in patients with angina (Class I-II), normal electrocardiogram and chest X-ray, the operative risk is low. On the other hand, patients with severe heart failure (Class IV NYHA), unstable angina or acute myocardial infarction have a high surgical risk. The exercise stress testing must be performed in some cases in order to identify preoperative factors (electrocardiographic ischemic changes, low functional capacity) that might affect the development of cardiac events after noncardiac surgery. When not possible a thallium-dipyridamole scintigraphy should be considered. We discuss preoperative indications for coronary angiography and coronary revascularization. Coronary artery bypass surgery must be thought based on clinic severity, therapeutic results, left ventricular function and patient age, among other factors.

[Efficacy and safety of adenosine triphosphate in the control of supraventricular paroxysmal tachycardia]. / Eficácia e segurança do trifosfato de adenosina na terminação de taquicardia paroxística supraventricular.

Our purpose was to assess the efficacy and safety of intravenous ATP for the acute termination of paroxysmal supraventricular tachycardia. There were 14 women and 10 men, aged 38 +/- 15 years. Three patients had evidence of structural heart disease (Ebstein's anomaly associated to atrial septal defect, operated mitral stenosis with insertion of a mechanical heart valve and CAD respectively). Twelve patients had Wolff-Parkinson-White syndrome and another had undergone surgical ablation of an accessory pathway. At the time of electrophysiologic testing, ATP was administered during episodes of paroxysmal supraventricular tachycardia, via a central vein, in incremental doses of 5, 10 and 20 mg followed by a flush of 10 c.c. of isotonic saline. The mechanism of the arrhythmia was orthodromic AV reentrant tachycardia in 19 (79%), AV nodal reentrant tachycardia in 4 (16.6%) and atrial tachycardia in one patient. The mean frequency of the tachycardia was 174 +/- 33 b.p.m. A dose of 5 mg was effective in 16 patients (66%), 5 required 10 mg and two required 20 mg for termination of the tachycardia. In the patient with atrial tachycardia ATP was not effective. The average time after injection to termination of the arrhythmia was 16 +/- 8 seconds. Orthodromic AV reentrant tachycardia was interrupted in the AV node limb in all but one patient and AV nodal reentry was terminated in the "slow-pathway" in three of the four patients. Nine patients had premature ventricular complexes, isolated or in couplets, after the termination of the SVT. Three patients had immediate recurrence of the SVT.(ABSTRACT TRUNCATED AT 250 WORDS)

[The diagnosis and ablation of accessory atrioventricular pathways in the initial electrophysiological exam: a new therapeutic modality in pre-excitation syndromes]. / Diagnóstico e ablação de vias acessórias aurículo-ventriculares no exame electrofisiológico inicial: nova modalidade terapêutica dos síndromes de pré-excitação.

OBJECTIVE: To describe the experience and results in the diagnosis and catheter ablation of atrioventricular accessory (AP) pathways during the initial electrophysiologic study. DESIGN: We performed catheter ablation at the time of an initial electrophysiologic study in 22 consecutive patients (12 W and 10 M, mean age 42 +/- 15) with Wolff-Parkinson-White syndrome or supraventricular tachycardia. SETTING: Cardiology Department at University Hospital. INTERVENTIONS: The precise AP mapping was performed with the ablation catheter (4 mm distal electrode and deflectable tip) according to the earlier ventricular activation during sinus rhythm or the earlier atrial activation during ventricular pacing or orthodromic reentrant tachycardia. For left-sided pathways the ablation catheter was positioned on the mitral annulus retrogradely across the aortic valve, while for right-sided pathways it was positioned on the tricuspid annulus or near the coronary sinus os. Radiofrequency energy was applied for 20-60 segs with 55-65 Volts. MEASUREMENTS AND RESULTS: Seventeen AP were manifest and five were concealed. AP were left lateral in 11 patients (50%), left posterior in 5, and right postero-septal, right posterior or antero-septal in 2 patients each. The ablation was initially successful in 18/22 (82%), with 9 +/- 8 radiofrequency applications. Mean duration of the entire procedure was 145 +/- 59 min and the fluoroscopy duration was 39 +/- min. There were no major complications. During 2-9 months of follow-up AP conduction returned in two patients. CONCLUSIONS: Radiofrequency catheter ablation of AP is effective and safe and can be performed at the time of an initial electrophysiologic test, avoiding the need for long-term antiarrhythmic drug therapy or surgical ablation.

[The use of Holter electrocardiography in permanent pacemaker users]. / Emprego da electrocardiografia de Holter em portadores de pacemaker permanente.

The authors selected 37 permanent pacemaker patients followed for eleven successive months, with symptomatology eventually related to the pacing system. An Holter ambulatory monitorization was performed to all of them during 24 hours. Twenty one had single chamber systems and the others double chamber. Twelve malfunctions were found in ten patients. Six due to "undersensing", 4 related to "oversensing", and 2 from loss of capture. Two patients had tachycardia pacemaker mediated. An inadequate mode of pacing was found in other two cases. Fifteen rhythm disturbances not related to the pacemaker systems were registered in thirteen patients: supra-ventricular in 9; ventricular greater than or equal to 3 degree of lown in 5; and 2nd degree A.V.B. Mobitz type I in one case. Four patients were submitted to surgical intervention in order to modify the mode of pacing. It was also necessary to reprogram ten patients. The Holter Ambulatory Electrocardiography revealed to be an important diagnostic method for the detection of intermittent malfunction of pacing systems. The occasional changes of cardiac rhythm not linked with pacing were also revealed.

[Atrial pacing and the exercise test in the evaluation of coronary disease. A comparative study]. / O pacing auricular e a prova de esforço na avaliação da doença coronária. Estudo comparativo.

OBJECTIVE: to compare the relative value of Atrial Pacing and Exercise Electrocardiography in the diagnosis of Myocardial Ischaemia. DESIGN: prospective study in patients referred for coronary cineangiography. SETTING: Cineangiography and Ergonometry Departments of Cardiology Service. Santa Maria Hospital. PATIENTS: 16 patients (mean age 52.4 +/- 6.3), 13 males and 3 females. All were submitted to Atrial Pacing, Exercise Test and Coronariography. RESULTS: both tests were concordant in all cases but one, with negative Atrial Pacing, positive Exercise Test and negative Coronariography. CONCLUSIONS: Atrial Pacing compares favourably with Exercise Test in the diagnosis of Coronary Ischaemic Disease. It may constitute a valid alternative in patients unable to perform a conclusive Exercise Test.

[Temporary pacing in the prevention and treatment of tachyarrhythmia]. / O pacing temporário na prevenção e tratamento das taquidisrritmias.

In this article cardiac pacing is approached as a method to prevent and treat tachyarrythmias. The authors describe both the ways and places of stimulation as well as the indication to its use. The risks and complications associated to this method are also mentioned. In conclusion they refer to it as an available alternative to the other forms of antiarrythmic therapy, emphasising its efficacy and safety.

[Endocrine arterial hypertension. Primary hyperaldosteronism]. / Hipertensão arterial endócrina. Hiperaldoesteronismo primário.

The authors emphasize some adrenal embryologic features, mainly the cortex and medulla relationships. After brief considerations both on the biosynthesis and physiologic actions of aldosterone, the Primary Hyperaldosteronism physiopathology is described. The clinical, biochemical and anatomic evidences are presented as a basis for both the Syndrome diagnosis and its subtypes. The theoretical and practical aspects of the diagnostic tests are also referred as a basis for the rationale of the medical and surgical therapeutic approach. Some clinical and biochemical similar aspects between the Syndrome of Hyperaldosteronism and Essential Hypertension with low renin, are put forward as a possible physiopathologic link that could eventually contribute for a better understanding of the pathogenesis of Essential Hypertension.

Persistent atrial standstill with atrial inexcitability.

Electrophysiologic studies including His bundle recording, atrial, and ventricular stimulation, were performed in three symptomatic patients with persistent atrial standstill of unknown etiology. The rhythm was junctional in two cases and ventricular in one. In two cases, evidence suggestive of associated impairment of the His bundle conduction system was found. The atria were inexcitable at multiple sites and no retrograde conduction to the right atrium could be elicited by ventricular pacing. Follow-up in the three cases, respectively for 48, 42 and 12 months after pacemaker implantation, revealed no return of spontaneous atrial electrical activity.