João Ricardo Cordeiro Fernandes

Atenolol blunts blood pressure increase during dynamic resistance exercise in hypertensives

AIMS This study was conducted to determine whether atenolol was able to decrease BP level and mitigate BP increase during dynamic resistance exercise performed at three different intensities in hypertensives. METHODS Ten essential hypertensives (systolic/diastolic BP between 140/90 and 160/105mmHg) were blindly studied after 6 weeks of placebo and atenolol. In each phase, volunteers executed, in a random order, three protocols of knee-extension exercises to fatigue: (i) one set at 100% of 1RM; (ii) three sets at 80% of 1RM; and (iii) three sets at 40% of 1RM. Intra-arterial radial blood pressure was measured throughout the protocols. RESULTS Atenolol decreased systolic BP maximum values achieved during the three exercise protocols (100% = 186 ± 4 vs. 215 ± 7, 80% = 224 ± 7 vs. 247 ± 9 and 40% = 223 ± 7 vs. 252 ± 16mmHg, P < 0.05). Atenolol also mitigated an increase in systolic BP in the first set of exercises (100% =+38 ± 5 vs.+54 ± 9; 80% =+68 ± 11 vs. +84 ± 13 and 40% =+69 ± 7 vs.+84 ± 14, mmHg, P < 0.05). Atenolol decreased diastolic BP values and mitigated its increase during exercise performed at 100% of 1RM (126 ± 6 vs. 145 ± 6 and +41 ± 6 vs.+52 ± 6, mmHg, P < 0.05), but not at the other exercise intensities. CONCLUSIONS Atenolol was effective in both reducing systolic BP maximum values and mitigating BP increase during resistance exercise performed at different intensities in hypertensive subjects.

Paradoxical Aortic Stenosis: Simplifying the Diagnostic Process

DOI: 10.5935/abc.20180075 Figure 1 – Algorithm proposed for the diagnosis of paradoxical aortic stenosis. * In patients with BMI above 30 kg/m2, we must use 0.5 cm2/m2 value as reference for iAVA. AS: aortic stenosis; AVA: aortic valve area; Vel: jet velocity; Grad: gradient; EF: ejection fraction; iAVA: indexed aortic valve area; sBP: systolic blood pressure; CT: computed tomography. Paradoxical AS Recognition AVA ≤ 1.0 cm2 Vel < 4 m/s ou Grad médio < 40 mmHg EF ≥ 50%

Topographic Pattern of Valve Calcification: A New Determinant of Disease Severity in Aortic Valve Stenosis

The pathophysiology of degenerative aortic valve stenosis (AS) is intimately related to the development of calcific deposits in the valve structure. Multidetector computed tomography (MDCT), a reliable method to delineate the tridimensional heart geometry, has been shown to accurately quantify the

Recommendation of Early Surgery in Primary Mitral Regurgitation: Pros and Cons

DOI: 10.5935/abc.20160107 Primary mitral valve regurgitation is the most frequent valvular pathology, affecting approximately 1.7% of the population, with prolapsed mitral as the highlighted etiology.1 In developing countries, such as Brazil, rheumatic fever is still widely prevalent (18.6/1000), and affects about 15.6 million people worldwide.2,3 Currently, the recommendation of mitral surgery for asymptomatic patients is very controversial, since the indication of valvular intervention for symptoms, left ventricular disfunction and dilatation, recent onset atrial fibrillation or pulmonary arterial hypertension is well consolidated in literature (Table 1).4-6 One strand defends the concept of “watchful waiting”, highlighting operative risks and morbi-mortality in early implantation of a bioprosthesis, as well as the benign history of asymptomatic mitral regurgitation. On the other hand, a second group advocates for the indication of early surgery, showing, through literature, that mitral valve repair, in these conditions, reduces surgical mortality and increases survival for these patients.7-11

Patient Management with Metallic Valve Prosthesis during Pregnancy and Postpartum Period.

Prosthetic thrombosis is a rare complication, but it has high mortality and morbidity. Young women of childbearing age that have prosthetic heart valves are at increased risk of thrombosis during pregnancy due to changes in coagulation factors. Anticoagulation with adequate control and frequent follow-up if pregnancy occurs must be performed in order to prevent complications related to anticoagulant use. Surgery remains the treatment of choice for prosthetic heart valve thrombosis in most clinical conditions. Patients with metallic prosthetic valves have an estimated 5% risk of thrombosis during pregnancy and maternal mortality of 1.5% related to the event. Anticoagulation with vitamin K antagonists during pregnancy is related to varying degrees of complications at each stage of the pregnancy and postpartum periods. Warfarin sodium crosses the placental barrier and when used in the first trimester of pregnancy is a teratogenic agent, causing 1-3% of malformations characterized by fetal warfarin syndrome and also constitutes a major cause of miscarriage in 10-30% of cases. In the third trimester and at delivery, the use of warfarin is associated with maternal and neonatal bleeding in approximately 5 to 15% of cases, respectively. On the other hand, inadequate anticoagulation, including the suspension of the oral anticoagulants aiming at fetal protection, carries a maternal risk of about 25% of metallic prosthesis thrombosis, particularly in the mitral valve. This fact is also due to the state of maternal hypercoagulability with activation of coagulation factors V, VI, VII, IX, X, platelet activity and fibrinogen synthesis, and decrease in protein S levels. The Registry of Pregnancy and Cardiac Disease (ROPAC), assessing 212 pregnant women with metal prosthesis, showed that prosthesis thrombosis occurred in 10 (4.7%) patients and maternal hemorrhage in 23.1%, concluding that only 58% of patients with metallic prosthesis had a complication-free pregnancy.

Betabloqueio com atenolol não reduz potência aeróbia nem muda limiares ventilatórios em hipertensos sedentários

Introduction: Aerobic exercise is recommended for the treatment of hypertension. Its intensity can be prescribed based on the percentage of maximum heart rate (% MHR) or peak oxygen consumption (VO2peak%) in which the ventilatory thresholds (VT ) are achieved. However, some hypertensive patients who begin aerobic training may be receiving beta-blockers, which can influence these parameters. Objective: To investigate the effects of atenolol on VT of sedentary hypertensive patients. Methods: Nine volunteers performed two cardiopulmonary exercise tests until exhaustion after 4 weeks of treatment with atenolol (25 mg orally twice daily) and with placebo, administered in a fixed order and in a blinded manner. During the tests, heart rate (HR), blood pressure (BP), VO 2 at rest, anaerobic threshold (AT ), respiratory compensation point (RCP) and peak effort were analyzed. Results: VO2 increased progressively throughout the exercise and the values were similar for both treatments. Systolic blood pressure and heart rate also increased progressively during the exercise, but their absolute values were significantly lower with atenolol. However, the increase in systolic BP and HR during exercise was similar in both treatments. Thus, the % of MHR and %VO 2peak at which LA and PCR were achieved were not different between placebo and atenolol. Conclusion: Atenolol, at a dosage of 50mg/day, did not affect the % of VO 2peak and % of MHR corresponding to the VTs, which confirms that prescription of training intensity based on these percentages is adequate to hypertensive patients receiving beta-blockers.