Rafael Amorim Belo Nunes

Gender-related associations of genetic polymorphisms of α-adrenergic receptors, endothelial nitric oxide synthase and bradykinin B2 receptor with treadmill exercise test responses

Background Treadmill exercise test responses have been associated with cardiovascular prognosis in individuals without overt heart disease. Neurohumoral and nitric oxide responses may influence cardiovascular performance during exercise testing. Therefore, we evaluated associations between functional genetic polymorphisms of α-adrenergic receptors, endothelial nitric oxide synthase, bradykinin receptor B2 and treadmill exercise test responses in men and women without overt heart disease. Methods We enrolled 766 (417 women; 349 men) individuals without established heart disease from a check-up programme at the Heart Institute, University of São Paulo Medical School. Exercise capacity, chronotropic reserve, maximum heart-rate achieved, heart-rate recovery, exercise systolic blood pressure (SBP), exercise diastolic blood pressure (DBP) and SBP recovery were assessed during exercise testing. Genotypes for the α-adrenergic receptors ADRA1A Arg347Cys (rs1048101), ADRA2A 1780 C>T (rs553668), ADRA2B Del 301–303 (rs28365031), endothelial nitric synthase (eNOS) 786 T>C (rs2070744), eNOS Glu298Asp (rs1799983) and BK2R (rs5810761) polymorphisms were assessed by PCR and high-resolution melting analysis. Results Maximum SBP was associated with ADRA1A rs1048101 (p=0.008) and BK2R rs5810761 (p=0.008) polymorphisms in men and ADRA2A rs553668 (p=0.008) and ADRA2B rs28365031 (p=0.022) in women. Maximum DBP pressure was associated with ADRA2A rs553668 (p=0.002) and eNOS rs1799983 (p=0.015) polymorphisms in women. Exercise capacity was associated with eNOS rs2070744 polymorphisms in women (p=0.01) and with eNOS rs1799983 in men and women (p=0.038 and p=0.024). Conclusions The findings suggest that genetic variants of α-adrenergic receptors and bradykinin B2 receptor may be involved with blood pressure responses during exercise tests. Genetic variants of endothelial nitric oxide synthase may be involved with exercise capacity and blood pressure responses during exercise tests. These responses may be gender-related.

Exercise-Induced Muscle Vasodilatation and Treadmill Exercise Test Responses in Individuals without Overt Heart Disease

Background: The beneficial effects of exercise on cardiovascular health may be related to the improvement in several physiologic pathways, including peripheral vascular function. The aim of this study was to evaluate the relationship between cardiovascular responses during the treadmill exercise test and exercise-induced muscle vasodilatation in individuals without overt heart disease. Methods: The study included 796 asymptomatic subjects (431 females and 365 males) without overt heart disease. We evaluated the heart rate (chronotropic reserve and heart rate recovery), blood pressure (maximum systolic and diastolic blood pressure as well as systolic blood pressure recovery) and exercise capacity during symptom-limited treadmill exercise testing. Exercise-induced muscle vasodilatation was studied with venous occlusion plethysmography and estimated by forearm blood flow and vascular conductance responses during a 3-min handgrip maneuver. Results: Forearm blood flow increase during the handgrip exercise was positively associated with heart rate recovery during treadmill exercise testing (p < 0.001). Forearm vascular conductance increase during the handgrip exercise was inversely associated with exercise diastolic blood pressure during exercise treadmill testing (p = 0.038). No significant association was found between exercise capacity and exercise-induced muscle vasodilation. Conclusion: In a sample of individuals without overt heart disease, exercise-induced muscle vasodilatation was associated with heart rate and blood pressure responses during treadmill exercise testing, but was not associated with exercise capacity. These findings suggest that favorable hemodynamic and chronotropic responses are associated with better vasodilator capacity, but exercise capacity does not predict muscle vasodilatation.

Genetic associations of bradykinin type 2 receptor, alpha-adrenoceptors and endothelial nitric oxide synthase with blood pressure and left ventricular mass in outpatients without overt heart disease

Background Physiological pathways such as bradykinin, renin-angiotensin, neurohormones and nitric oxide have been shown to play an important role in the regulation of cardiovascular function. Genetic variants of these pathways may impact blood pressure and left ventricular (LV) mass in different populations. To evaluate associations of genetic polymorphisms of bradykinin B2 receptor (BDKRB2), alpha-adrenergic receptors (ADRA) and endothelial nitric oxide synthase (eNOS) on the modulation of the blood pressure and the left ventricular mass. Methods We enrolled 758 individuals without overt heart disease. Blood pressure was estimated by auscultatory method during the clinical examination. Left ventricular (LV) mass was assessed by echocardiography. Genotypes for ADRA1A rs1048101, ADRA2A rs553668, ADRA2B rs28365031, eNOS rs2070744, eNOS rs1799983, and BDKRB2 rs5810761 polymorphisms were assessed by high-resolution melting analysis. Results BDKRB2 polymorphism rs5810761 was associated with blood pressure. Carriers of DD genotype had higher levels of SBP and DBP than carrier of II genotype (p = 0.013 and p = 0.007, respectively). eNOS polymorphism rs1799983 was associated with DBP. Carriers of GT genotype had lower levels of DBP than carriers of GG genotype (p = 0.018). eNOS polymorphism rs2070744 was associated with LV mass. Carriers of TC genotype had higher LV mass than carriers of TT genotype (p = 0.028). Conclusions In a cohort of individuals without overt heart disease, the BDKRB2 rs5810761 polymorphism (DD genotype carriers) were associated higher systolic and diastolic blood pressures, and the eNOS rs1799983 polymorphism (T allele carriers) were associated with lower diastolic blood pressure. The eNOS rs2070744 polymorphism (C allele carriers) was associated with higher left ventricular mass. These data suggest that eNOS and bradykinin receptor genetic variants may be potential markers of common cardiovascular phenotypes.

Case 2/2018 - 73-Year-Old Male with Ischemic Cardiomyopathy, Cachexia and Shock

His physical examination (April 29, 2004) showed emaciation, dehydration, heart rate of 80 bpm, inaudible blood pressure, increased jugular venous pressure, lungs with inspiratory wheezes, regular heart rhythm and no heart murmur on cardiac auscultation, liver palpable 3 cm from the right costal margin, and mild edema of the lower limbs. The patient received 1500 mL of 0.9% saline solution, which increased his blood pressure to 90/70 mm Hg.

Case 6 - Woman with Ischemic Heart Disease Admitted due to Chest Pain and Shock

At the physical examination, the heart rate (HR) was 100 beats per minute, blood pressure was 100/60 mmHg. Pulmonary assessment was normal. The heart examination disclosed a ++/ 6+ systolic murmur in the mitral area. The remainder of the physical examination was normal. The electrocardiogram (1h 19 min; Dec 30, 2009) showed sinus rhythm, HR of 103 bpm, PR interval of 122 ms, QRS duration of 159 ms, QT interval of 367 ms, and corrected QT of 480 ms.

Case 5/2017 - A 28-Year-Old Woman with Cor Pulmonale Due to Pulmonary Hypertension Secondary to Chronic Pulmonary Thromboembolism

Her technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA) radioaerosol inhalation lung scintigraphy (May 21, 2008) revealed marked hypoventilation of the left lung and retention of the radiotracer in the right peri-hilar region, suggestive of a parenchymal process. The use of 99mTC human albumin macroaggregates (99mTC MAA) revealed no perfusion in the left lung and perfusion defects in the right lung base.

Cardiac Catheterization in a Patient with Obstructive Hypertrophic Cardiomyopathy and Syncope

Figure 1 – Panel A, extrinsic compression of the diagonal branch and septal branches (white arrows). Panel B, ventriculography of the right ventricle (RV) and left ventricle (LV), showing significant interventricular septal (IVS) hypertrophy during diastole and Panel C, LV outflow tract obstruction during end-systole. A 35-year-old man sought medical care for recurrent syncope episodes related to moderate exertion in the past 2 months. Upon physical examination, the presence of a rude systolic murmur on the left sternal border was identified. The echocardiogram disclosed a moderate increase in the left atrium and significant hypertrophy of the interventricular septum with an estimated maximum diastolic diameter of 31 mmHg and a maximum left ventricular outflow tract gradient of 56 mmHg. The 24-hour Holter assessment showed the presence of frequent ventricular extrasystoles and an episode of nonsustained ventricular tachycardia. He was prescribed metoprolol 50 mg daily and, based on the high risk of sudden death, received an implantable cardioverter-defibrillator.

Case 4/2017 - Young Male Marathoner with Heart Failure Due to Dilated Cardiomyopathy

According to his father, the patient had convulsions during childhood and an episode of rheumatic fever during adolescence, having undergone antibiotic prophylaxis with benzathine penicillin for 2 years, which was discontinued spontaneously, without disease recurrence. In addition, he reported recent alcohol abuse and depressive symptoms, but neither his family nor friends knew any illicit drug use.

Alpha2A-adrenergic receptor and eNOS genetic polymorphisms are associated with exercise muscle vasodilatation in apparently healthy individuals

Purpose Muscle vasodilatation during exercise has been associated with cardiovascular health and may be influenced by genetic variability. The purpose of this study was to evaluate functional genetic polymorphisms of physiologic pathways related to the regulation of the cardiovascular function (alpha-adrenergic receptors, endothelial nitric oxide synthase and bradykinin B2 receptor) and exercise muscle vasodilatation in apparently healthy men and women. Methods We enrolled 689 individuals without established cardiovascular disease that had attended a check-up program. The vasodilatation was studied with venous occlusion plethysmography and determined by the increase of vascular conductance during handgrip exercise. Genotypes for ADRA1A Arg347Cys (rs1048101), ADRA2A 1780 C > T (rs553668), ADRA2B Del 301–303 (rs28365031), eNOS 786 T > C (rs2070744), eNOS Glu298Asp (rs1799983) and BDKRB2 (rs5810761) polymorphisms were assessed by polymerase chain reaction followed by high resolution melting analysis. Results The eNOS rs2070744 polymorphism was significantly associated with forearm vascular conductance during exercise in women. Women with CC genotype showed higher vasodilatation than carriers of TC and TT genotypes (p = 0.043). The ADRA2A rs553668 polymorphism was significantly associated with forearm vascular conductance during exercise in men. Men with TT genotype had higher vasodilatation than carriers of CT and CC genotypes (p = 0.025). Conclusions eNOS rs207074 polymorphism in women and ADRA2A rs553668 polymorphism in men were associated with the increase of forearm vascular conductance during handgrip exercise. These findings suggest that eNOS and ADRA2A genetic polymorphisms may be potential markers of exercise muscle vasodilatation.

Case 2/2016 - 76-Year-Old Male with Hypertensive Heart Disease, Renal Tumor and Shock

The patient is a 76-year-old male with heart disease, hospitalized due to shock and respiratory failure. At the age of 50 years, he was referred to InCor to investigate non-anginal chest pain. His exercise test was negative for ischemia. Physical examination at that time was normal, except for slightly elevated blood pressure (BP: 140/90 mm Hg) and obesity (weight of 95 kg, height of 1.70 m; body mass index = 32.9kg/m2). Electrocardiogram revealed sinus bradycardia, and the new exercise test was negative. Echocardiogram on December 5, 1985, revealed normal valves and the following parameters: aortic root, 35 mm; left atrium, 44 mm; right ventricle, 21 mm; left ventricle, 53 mm; left ventricular ejection fraction, 60%; septal and posterior wall thickness, 11 mm. Laboratory tests on December 6, 1985, were as follows: hemoglobin, 13.1 g/dL; hematocrit, 41%; leukocytes, 7,100/mm3; platelets, 268,000/mm3; glycemia, 118 mg/dL; creatinine, 1 mg/dL; sodium, 140 mEq/L; potassium, 4.5 mEq/L; total bilirubin, 0.54 mg/dL; direct bilirubin, 0.15 mg/dL; ALT, 76 IU/L; alkaline phosphatase, 227 IU/L (normal< 170 IU/L); total proteins, 78 g/dL; albumin, 4.3 g/dL; and globulins, 3.5 g/dL. The patient was lost to follow-up at Incor until March 1996, when, at the age of 60 years, he experienced chest pressure, sweating and dyspnea on exertion, which, in a few weeks, progressed to dyspnea at rest. On that occasion, he reported smoking and having arterial hypertension, hyperuricemia, and lost his father due to myocardial infarction, and his mother due to stroke. His physical examination on March 6, 1996, was normal, showing: weight, 104 kg; height, 1.70 m; BP, 160/90 mm Hg; heart rate, 80 bpm. On that same day, his ECG revealed sinus rhythm, heart rate of 78 bpm and right bundle-branch block (RBBB) (Figure 1), and his laboratory tests were as follows: urea, 20 mg/dL; creatinine, 1.3 mg/dL; and normal levels of myocardial injury markers. Figure 1 ECG: sinus rhythm, right bundle-branch block. Exercise test on March 8, 1996, showed: maximum heart rate achieved, 139 bpm; duration of 5 min; initial BP, 150/90 mm Hg, and at peak exercise, 186/100 mm Hg, with no ischemic changes. Echocardiogram on March 5, 1996, revealed left ventricular apical and laterobasal hypokinesia, and ejection fraction of 70%. Coronary angiography on March 11, 1996, revealed 50% lesions in the anterior descending and circumflex branches of the left coronary artery. Ventriculography showed moderate diffuse hypokinesia. Atenolol (50 mg), enalapril (10 mg) and acetylsalicylic acid (100 mg) were prescribed. New exercise test on February 17, 1998, was negative for ischemia, and laboratory tests showed: cholesterol, 158 mg/dL; HDL-C, 24 mg/dL; LDL-C, 65 mg/dL; triglycerides, 347 mg/dL; glycemia, 105 mg/dL; uric acid, 7.4 mg/dL; creatinine, 1.0 mg/dL. Echocardiogram on that same day revealed septal and posterior wall thickness of 12 mm, left ventricle of 52 mm, ejection fraction of 63%, and normal motility. The patient remained asymptomatic from the cardiovascular viewpoint for more than 10 years until, at the age of 72 years, he experienced dyspnea that rapidly progressed in 20 days to dyspnea at rest, accompanied by tachycardic palpitations. He was admitted to another hospital, diagnosed with heart failure and tachycardia with wide QRS complex, initially identified as supraventricular with aberrancy, and then, as sustained ventricular tachycardia, which was reversed with amiodarone. He reported undergoing surgery to treat a malignant neoplasm of the urinary bladder at the age of 68 years. In addition, he reported undergoing gastrectomy because of peptic ulcer, but did not inform exactly when. Electrocardiogram on August 7, 2008, showed tachycardia with wide QRS complex, heart rate of 150 bpm, with positive QRS from V1 to V6 (Figure 2). After reversion, the ECG evidenced RBBB with atrioventricular dissociation (Figure 3). Figure 2 ECG: ventricular tachycardia and pure R waves from V1 to V6. Figure 3 ECG: atrioventricular dissociation, right bundle-branch block. Physical examination on September 5, 2008, revealed BP of 160/90 mm Hg, heart rate of 68 bpm, normal pulmonary and cardiac auscultations, and mild lower limb edema. Electrocardiogram on September 5, 2008, revealed sinus rhythm, RBBB and multifocal ventricular extrasystoles (Figure 4). Figure 4 ECG: sinus rhythm, right bundle-branch block. Carvedilol (6.25 mg), furosemide (40 mg), enalapril (20 mg) and amiodarone (200 mg) were prescribed to the patient, who was referred to the arrhythmia outpatient clinic. Laboratory tests in February 2009 revealed: hemoglobin, 9.8 g/dL; hematocrit, 34; VCM, 65 fL; RDW, 20.3%; leukocytes, 8,000/mm3; platelets, 377,000/mm3; total cholesterol, 117 mg/dL; HDL-C, 25 mg/dL; LDL-C, 62 mg/dL; triglycerides, 123 mg/dL; glycemia, 125 mg/dL; creatinine, 1.72 mg/dL; urea, 48 mg/dL; sodium, 137 mEq/L; potassium, 5.3 mEq/L; calcium, 13 mg/dL; ionic calcium, 1.9 mmol/L; TSH, 2.4 µU/mL; TP (INR), 1.0; TTPA (rel), 1.05; iron, 23 µg/dL; transferrin saturation, 5%. Urinalysis: density, 1009; pH, 6.0; leukocytes, 2,000/mL; and red blood cells, 2,000/mL. Coronary angiography on February 3, 2009, evidenced irregularities in the anterior descending branch of the left coronary artery, 60% in the first diagonal branch, and irregularities in the circumflex artery and right coronary artery. The left ventricle was dilated and had moderate diffuse hypokinesia. Hemodynamic parameters were: aorta (S/D/M) 160/80/107 mm Hg; left ventricle (S/D/ED) 160/05/20 mm Hg. The patient was admitted in February 2009 for electrophysiological study, and was not on amiodarone at that time. Upper digestive endoscopy on February 12, 2009, showed a previously operated on stomach (Billroth I gastrectomy) and severe alkaline reflux gastritis. During electrophysiological study on February 13, 2009, extra-stimuli induced badly-tolerated monomorphic ventricular tachycardia [DI(+), aVL(+/-), lower axis, with positivity from V1 to V6, no transition] with degeneration to fibrillation after reversion attempt with burst. Successful defibrillation obtained with 200 J. Echocardiogram on February 19, 2009, showed: diameters of the aorta and left atrium, 34 mm and 55 mm, respectively; septum, 12 mm; posterior wall, 10 mm; left ventricle diameters, 59/42 mm; left ventricular ejection fraction, 35%; akinesia of the apical and inferolateral walls; hypokinesia of the other walls; and severe mitral regurgitation. Abdominal ultrasound on February 20, 2009, revealed dilation of the infrarenal aorta, and stone and nodule in the lower pole of the right kidney. Abdominal computed tomography on February 25, 2009, revealed a solid nodule in the lower pole of the right kidney, measuring 2.9x2.9 cm, with contrast uptake. Implantable cardioverter defibrillator (ICD) was indicated as primary prophylaxis of sudden death and to support beta-blocker use, because the patient experienced bradycardia and arterial hypotension when an increase in beta-blocker dose was attempted. The ICD implantation was performed on February 17, 2012. The patient was referred to a urologist and discharged from the hospital with the following daily prescription: carvedilol, 50 mg; hydralazine, 75 mg; hydrochlorothiazide, 25 mg; atorvastatin, 10 mg; amiodarone, 200 mg; isosorbide mononitrate, 20 mg; omeprazole, 20 mg; and ferrous sulfate, 80 mg. During the patients follow-up on an outpatient clinic basis, he developed dyspnea on moderate exertion. On ICD assessment in March 2012, the device was functioning normally and had recorded one shock in February 2011 during an episode of ventricular tachycardia. The patient was hospitalized again on June 17, 2012, with consciousness lowering and arterial hypotension for one day. On admission, the patient was drowsy, dehydrated (+/4+) and pale (2+/4+), and had non-productive cough, and neither fever nor dyspnea. His BP was 80/60 mm Hg, heart rate, 60 bpm, and room air O2 saturation ranging from 88% to 90%. Pulmonary auscultation revealed crepitant rales on the middle third of the right hemithorax. Cardiac auscultation showed irregular rhythm, low heart sounds and no heart murmur. The abdomen showed no change. There was no edema and the pulses were thin. Glasgow coma scale was as follows: eyes - opens eyes in response to voice (3); verbal - confused, disoriented (4); motor - obeys commands (6); no motor deficit; equal pupils reactive to light. Volume administration and antibiotic therapy with ceftriaxone and clarithromycin were initiated. Laboratory tests on June 17, 2012, revealed: hemoglobin, 11.1 g/dL; hematocrit, 36%; leukocytes, 10,040 (10% band neutrophils, 77% segmented neutrophils, 4% eosinophils, 8% lymphocytes, 1% monocytes); platelets, 110,000/mm3; PCR, 79.16 mg/L; CK-MB, 2.45 ng/mL; troponin I < 0.006 ng/mL; urea, 135 mg; creatinine, 4.55 mg/dL; sodium, 140 mEq/L; potassium, 3.3 mEq/L; calcium, 6.5 mEq/L; magnesium, 2.0 mEq/L; BNP, 273 pg/mL; total bilirubin, 0.54 mg/dL; direct bilirubin, 0.27 mg/dL; TP(INR) 1.1; TTPA(rel) 1.18. Those antibiotics were replaced by the piperacillin-tazobactam association, and later, by vancomycin. Laboratory tests on June 19, 2012, were as follows: hemoglobin, 10.9 g/dL; hematocrit, 34%; VCM, 89 fL; leukocytes, 7,050/mm3 (neutrophils 85%, eosinophils 2%, lymphocytes 9%, 4% monocytes); platelets, 79,000/mm3; PCR, 121.15 mg/dL; urea, 135 mg/dL; creatinine, 4.27 mg/dL (glomerular filtration: 14 mL/min/1.73m2); magnesium, 1.90 mEq/L; sodium, 137 mEq/L; potassium, 3.5 mEq/L; ionized calcium, 1.69 mmol/L; venous lactate, 13 mg/dL; venous pH, 7.33; venous bicarbonate, 23 mEq/L. Despite treatment with volume administration, antibiotics and vasoactive amines, the patient remained shocked and died on June 20, 2012.