Low coronary perfusion pressure is associated with endocardial fibrosis in a rat model of volume overload cardiac hypertrophy

No remodelamento que se segue às sobrecargas de volume não é descrito o aumento de fibrose miocárdica. Após o infarto, entretanto, há hipertrofia do miocárdio remoto com acúmulo de fibrose, particularmente no subendocárdio. Na fístula aorto-cava, tal como no infarto, é possível que a queda da pressão de perfusão coronariana interfira com a fibrose cardíaca. OBJETIVO: Investigar o papel das mudanças hemodinâmicas agudas sobre a fibrose cardíaca na fístula aorto-cava. MÉTODO: Ratos Wistar submetidos a fístula aorto-cava, seguidos por 4 e 8 semanas, constituíram 4 grupos, fístula aorto-cava 4 e fístula aorto-cava 8 (10 ratos cada) e seus respectivos controles (sham-operated controls - Sh), Sh4 e Sh8 (8 ratos cada). A hemodinâmica foi realizada 1 semana após a cirurgia. A hipertrofia e a fibrose foram quantificadas ao final do seguimento pelo diâmetro dos miócitos e pela fração de volume do colágeno. RESULTADOS: Comparados com Sh4 e Sh8, a pressão de pulso, a pressão diastólica final do ventrículo esquerdo e a +dP/dt foram maiores em fístula aorto-cava 4 e fístula aorto-cava 8, enquanto a -dP/dt foi similar. A pressão estimada da perfusão coronariana (mmHg) foi menor em fístula aorto-cava 8 (52,6±4,1) do que em Sh8 (100,8±1,3), mas comparável entre fístula aorto-cava 4 (50,0±8,9) e Sh4 (84,8±2,3). O diâmetro dos miócitos foi maior em fístula aorto-cava 8 e a fibrose intersticial e subendocárdica maior em fístula aorto-cava 4 e fístula aorto-cava 8. Houve correlação inversa e independente da pressão de perfusão coronariana com a fibrose subendocárdica (r2=0,86; p<0,0001) e das pressões sistólica (r2=0,73; p=0,0035) e diastólica final do ventrículo esquerdo (r2=0,55; p=0.0124) com a fibrose intersticial. CONCLUSÃO: A queda precoce da pressão de perfusão coronariana e o aumento das pressões ventriculares após a fístula aorto-cava associam-se com fibrose miocárdica subseqüente.

A fibrose subendocárdica que acompanha o remodelamento ventricular do infarto do miocárdio está associada a redução da pressão de perfusão coronariana durante a fase aguda / Subendocardial fibrosis in remote myocardium results from reduction of coronary driving pressure during acute infarction in rats

OBJECTIVE: To investigate the role of hemodynamic changes occurring during acute MI in subsequent fibrosis deposition within non-MI. METHODS: By using the rat model of MI, 3 groups of 7 rats each [sham, SMI (MI <30 percent), and LMI (MI >30 percent)] were compared. Systemic and left ventricular (LV) hemodynamics were recorded 10 minutes before and after coronary artery ligature. Collagen volume fraction (CVF) was calculated in picrosirius red-stained heart tissue sections 4 weeks later. RESULTS: Before surgery, all hemodynamic variables were comparable among groups. After surgery, LV end-diastolic pressure increased and coronary driving pressure decreased significantly in the LMI compared with the sham group. LV dP/dt max and dP/dt min of both the SMI and LMI groups were statistically different from those of the sham group. CVF within non-MI interventricular septum and right ventricle did not differ between each MI group and the sham group. Otherwise, subendocardial (SE) CVF was statistically greater in the LMI group. SE CVF correlated negatively with post-MI systemic blood pressure and coronary driving pressure, and positively with post-MI LV dP/dt min. Stepwise regression analysis identified post-MI coronary driving pressure as an independent predictor of SE CVF. CONCLUSION: LV remodeling in rats with MI is characterized by predominant SE collagen deposition in non-MI and results from a reduction in myocardial perfusion pressure occurring early on in the setting of MI

Chagas' heart disease: evolutive evaluation of electrocardiographic and echocardiographic parameters in patients with the indeterminate form

OBJECTIVE: To identify and associate potential electrocardiographic and echocardiographic changes in patients with the indeterminate form of Chagas' disease during long-term follow-up. METHODS: One hundred sixty patients underwent standard electrocardiography and two-dimensional guided M-mode echocardiography for left ventricular ejection fraction determination. Patients were followed up for 98.6Ý30.4 months, undergoing repeat electrocardiographic studies at 6-month intervals and echocardiographic studies at 12-month intervals. RESULTS: Based on the electrocardiographic findings, the patients were divided into group I, 125 patients (78.6 percent) with normal electrocardiograms throughout follow-up, and group II, 34 patients (21.3 percent) who developed electrocardiographic changes. Group II was further divided into group IIA (9 patients, 5.6 percent) with permanent electrocardiographic changes, group IIB (14 patients, 8.8 percent) with transitory electrocardiographic changes, and group IIC (11 patients, 6.9 percent) with changes appearing only on the final electrocardiogram. Left ventricular ejection fractions remained normal in the entire population studied and did not differ among groups. CONCLUSION: The indeterminate form of Chagas' disease clearly represents a benign condition with a favorable long-term prognosis. Although some patients develop electrocardiographic changes, left ventricular systolic function is well preserved

Aneurisma apical e hipertrofia ventricular esquerda / Apical aneurysm and left ventricular hypertrophy

A 59-year-old woman presented with an embolic transient ischemic attack and a history of controlled hypertension for 16 years. Both echocardiogram and MRI showed severe biventricular hypertrophy and an apical aneurysm with a thrombus. The occurrence of an apical aneurysm in the presence of cardiac hypertrophy is a rare finding and has been described in patients with hypertrophic cardiomyopathy. However, it has not been reported in patients with systemic arterial hypertension. In this patient the lack of a relationship between the severity of the hypertrophy and the levels of blood pressure, together with the presence of histologic disorganization of myocardial cardiac muscle cells by endomyocardial biopsy suggested the diagnosis of hypertrophic cardiomyopathy.

Disfunçäo sistólica e diastólica na hipertensäo arterial sistêmica com hipertrofia ventricular esquerda / Systolic and diastolic dysfunction in systemic hypertension with left ventricular hypertrophy

A hipertrofia ventricular esquerda é a adaptação cardíaca ao aumento da pós-carga, que caracteriza a doença cardíaca hipertensiva. O comprometimento das propriedades diastólicas do ventrículo esquerdo é uma das primeiras conseqüências dessa adaptação. A insuficiência cardíaca tem sido associada à disfunção diastólica. A clínica demonstra que a redução da pressão arterial age favoravelmente sobre esses sintomas. Por outro lado, os mecanismos responsáveis pela disfunção sistólica não estão devidamente esclarecidos. A avaliação do desempenho sistólico em condições dinâmicas apresenta resultados conflitantes. Na presença da hipertrofia, mesmo com déficit irreversível da contratilidade, é possível uma resposta normal da fração de encurtamento após o tratamento por meio da utilização da reserva de pré-carga. Alguns doentes com disfunção sistólica podem experimentar melhora após o controle da pressão arterial. Os fatores determinantes dessa resposta são as dimensões sistólicas e a etiologia renovascular da hipertensão. A inibição da enzima de conversão previne o acúmulo de colágeno intersticial e perivascular. É possível que o tratamento da doença renovascular, retirando a influência do sistema renina-angiotensiva, contribua para a melhora da função ventricular. A correlação observada entre a reserva de fluxo coronário e a disfunção sistólica corrobora para a participação do remodelamento da matriz extracelular na disfunção.

Falso diagnóstico de miocardiopatia hipertrófica em feocromocitoma / A false dignosis of hypertrophic myocardiopathy in pheochromocytoma

A 24 year-old man was admitted with hypertensive crises and diagnosis hypothesis of neurofibromathosis and pheochromocytoma with blood pressure of 150 x 110mmHg and in use of anti-hypertensive drugs. The electrocardiogram (EKG) showed left ventricle hypertrophy. An echocardiogram showed interventricular septum (IVS) thickness of 16mm, posterior wall (PW) thickness of 11mm (ratio IVS/PW was 1.4). Diastolic ventricular diameter was 39mm with gradient of 52mmHg and mild mitral-valve murmur by pulsate Doppler. Increased vanillylmandelic acid and metanephrines in a 24-hour sample of urine has confirmed diagnosis of pheochromocytoma within was localized by 131I metaiodobenzyl-guanidine scan and computerized axial tomography. The patient was submitted to right adrenalectomy. Blood pressure was normalized. Evaluation an year later revealed a healthy man with normal laboratory exams, EKG and echocardiogram. It seems that the hypertrophy was consequence of the hypertension and pheochromocytoma, was not hypertrophic cardiomyopathy.

Homem de 24 anos foi admitido com hipótese diagnóstica de neurofibromatose e feocromocitoma, com pressão arterial (PA) de 150 x 110 mmHg e em uso de medicação anti-hipertensiva. O eletrocardiograma mostrava sobrecarga de ventrículo esquerda. O ecocardiograma relatado com diagnóstico de miocardiopatia hipertrófica assimétrica, mostrava a espessura de septo interventricular de 16mm, parede posterior de 11mm, diâmetro diastólico de 39mm, com gradiente intra-ventricular de 52mmHg e discreta regurgitação proto-sistólica valvar mitral ao doppler pulsátil. As dosagens de ácido vanilmandélico e de metanefrina urinárias confirmaram a suspeita clínica de feocromocitoma, localizado através da cintilografia com metaiodobenzilguanidina e tomografia axial computadorizada. Um ano após adrenalectomia direita se encontra assintomático, com PA, alterações laboratoriais, eletrocardiográficas e ecocardiográficas normais, evidenciando assim, que a hipertrofia de ventrículo esquerdo (HVE) era conseqüência da hipertensão arterial do feocromocitoma e não da miocardiopatia hipertrófica. Esta regressão da HVE excluiu, assim, o falso diagnóstico de micardiopatia hipertrófica

Papel da hipertrofia e da funçäo ventricular esquerda sobre a ocorrência de arritmias ventriculares na hipertensäo arterial / The role of hypertrophy and left ventricular function on the ocurrence of ventricular arrhythmias in arterial hypertension

PURPOSE--To evaluate the role of left ventricular hypertrophy (LVH), left ventricular systolic function an other clinical parameters on prevalence and complexity of ventricular arrhythmias in hypertension. METHODS--Ventricular arrhythmias were studied in 39 hypertensives by 24 hours ambulatory electrocardiographic monitoring. Frequency and complexity of ventricular arrhythmias were compared among 3 groups: A and B, respectively without and with LVH, both with normal left ventricular function; and C with LVH and systolic dysfunction. LVH and systolic dysfunction were established echocardiographically. Linear regression analysis was performed in order to identify an independent correlation between clinical parameters and presence of arrhythmias. RESULTS--Group C patients were older and had significantly higher systolic and diastolic blood pressures, greater mass index, diastolic posterior wall thickness and end-systolic stress and increased prevalence of electrocardiographic strain. Left ventricular diastolic diameter in C group patients was increased only when compared to A group. Frequencies of cases with more than 10 ectopic ventricular beats/hour, pairs and nonsustained ventricular tachycardia episodes were all significantly increased in C when compared to B and to A. However, only left ventricular mass index or diastolic posterior wall thickness identified independently patients with ventricular arrhythmias. CONCLUSION--Left ventricular hypertrophy is the main predictor of potential high risk rhythm disturbances in hypertension

Papel da pressão arterial casual e do exercício e a influência de fatores clínicos sobre a hipertrofia ventricular esquerda na hipertensäo arterial / Role of Resting and Exercising Blood Pressure and Importance of Clinical Factors on Hypertensive Left Ventricular Hypertrop

PURPOSE--To evaluate the role of casual and exercise blood pressure as well as the importance of clinical factors on the presence and degree of left ventricular hypertrophy in hypertension. METHODS--Fifteen normotensives (control group) and 30 hypertensives, 14 of them with and 16 without left ventricular hypertrophy (groups with LVH and without LVH, respectively) were studied. LVH diagnosis was established when mass index was higher than 2 standard-deviations of the mean values calculated for each sex in control group. Resting, casual determined, and bicycle exercise systolic and diastolic blood pressures along with age, body surface area, sex and race distribution were compared between groups. In addiction, their relation with mass index as independent variables were also tested. RESULTS--Hypertensives in group with LVH had higher diastolic septal, posterior wall, and relative wall thicknesses. No significant statistical difference was observed neither in sex and race distribution, nor in age and body surface area between groups. Otherwise, there were significant differences in both resting and exercise blood pressure. In the entire population studied, left ventricular mass index significantly correlated with age (r=0,33, p=0,03) as well as with both casual (systolic - r=0,72, p=0,0001; diastolic - r=0,69, p=0,0001) and exercise (systolic - r=0,62, p=0,0001; diastolic - r=0,66, p=0,0001) blood pressures. However, linear regression analysis demonstrated that only resting systolic (p=0,0001) and exercise diastolic (p=0,0303) blood pressures were significant and independent determinants of mass index. CONCLUSION--Resting and exercising blood pressures are the main determinants of left ventricular hypertrophy in hypertension

Angioplastia percutânea e revascularizaçäo cirúrgica em hipertensäo renovascular: experiência no tratamento e seguimento de longo prazo em 124 pacientes / Percutaneous Angioplasty and Surgical Revascularization in Renovascular Hypertension. Experience on Long-Term Follow-up and Treatment in 124 Patients

PURPOSE--To report the experience in the treatment and long-term follow-up of patients with renovascular hypertension submitted to angioplasty and/or surgical revascularization, and to compare blood pressure and renal function responses to both treatment. METHODS--One hundred and twenty-four patients diagnosed with renovascular hypertension, divided, according to the etiology, as atherosclerosis (76 patients), fibromuscular dysplasia (32) and arteritis (16), were submitted to isolated or associated treatment of renal revascularization by percutaneous transluminal angioplasty (71 patients) or surgery (84). The patients were followed-up during 2.5 +/- 1.5 years and we evaluate blood pressure response and renal function preservation. In relation to blood pressure control, the patients were considered as cured when normotensives without antihypertensives, improved when normotensives with fewer drugs than previously, and unchanged, when out of these criteria. RESULTS--From 124 patients, 20 per cent were considered cured, 54 per cent improved and 26 per cent unchanged, after a mean follow-up of 2.5 +/- 1.5 years. Patients with atherosclerosis and fibromuscular dysplasia presented a higher rate of care and improvement after surgery. The blood pressure and the number of antihypertensive drugs decreased significantly during the follow-up among patients that cured or improved arterial hypertension, either after angioplasty (190 +/- 26/115 +/- 14 mmHg vs 130 +/- 34/85 +/- 7 mmHg. 2.70 vs 1.60 drugs) or after surgery (194 +/- 17/115 +/- 16 mmHg vs 143 +/- 18 mmHg vs 88 +/- 8 mmHg, 1.88 vs 1.51 drugs). It was also observed a significant decrease of serum creatinine among these patients. CONCLUSION--Renal revascularization in patients with renovascular hypertension, either by angioplasty or surgery, is beneficial to control blood pressure and to preserve renal function in the majority of patients

Hipertensão arterial e arritmias ventriculares complexas: evoluçäo após tratamento de longo prazo da pressäo arterial / Hypertension and complex ventricular arrhythmias: evolution following a long-term blood pressure treatment

PURPOSE--To evaluate the effects of long-term antihypertensive treatment in the frequency as well as in the complexity of ventricular arrhythmias in arterial hypertension. METHODS--Twenty three patients, 14 males and 11 whites, with mean age of 46 years, were submitted to 24 hours ambulatory electrocardiographic monitoring and echocardiographic studies before and 9 months after antihypertensive treatment. RESULTS--There was no significant serum potassium level alteration, but significant reductions of both systolic (from 192 +/- 29mmHg to 161 +/- 25mmHg) and diastolic (from 122 +/- 17mmHg to 99 +/- 16mmHg) blood pressure. Left ventricular percent of fiber shortening significantly increased, even though only from 26 +/- 9 per cent to 30 +/- 9 per cent, and end-systolic wall stress did not change at all (before 258 +/- 94 10(3) dyn/cm2, after 255 +/- 101 10(3) dyn/cm2). Left ventricular mass index showed significant but also a discrete reduction from 211 +/- 75g/m2 to 196 +/- 70g/m2. Ambulatory electrocardiographic monitoring did not show any significant decrease in neither ventricular ectopic beats nor in couplets. Non-sustained ventricular tachycardia episodes remained unchanged too. Four out of 8 patients with more than 30 ventricular ectopic beats per hour reduced it by more than 70 per cent. On the other hand, the number of patients with couplets was reduced from 10 to 8 whilst those with non-sustained ventricular tachycardia increased from 5 to 7. Furthermore, in 7 patients reevaluated 24 months thereafter results were not expressively dissimilar. CONCLUSION--In hypertensive patients with either severe degree of left ventricular hypertrophy or myocardial dysfunction, long-term blood pressure treatment that produce no impressive changes in these abnormalities also do not modify complex ventricular arrhythmias, in spite of a great reduction in the increase blood pressure

Funçäo sistólica do ventrículo esquerdo na hipertensäo arterial / Left ventricular systolic function in hypertension

Há várias décadas os fatores relacionados com o desempenho da funçäo sistólica durante o desenvolvimento da hipertrofia ventricular esquerda säo objeto de estudos em portadores de hipertensäo arterial. Neste artigo säo abordados os mecanismos fisiopatológicos envolvidos na adaptaçäo do coraçäo à sobrecarga hemodinâmica presente na hipertensäo arterial. Os fatores relacionados à transformaçäo da hipertrofia fisiológioca em patológica säo analisados com base em avanços, recentemente alcançados no estudo das alteraçöes dos miócitos de um lado e das transformaçöes que ocorrem no tecido intersticial de outro. A influência que o tratamento anti-hipertensivo pode representar para a preservaçäo do desempenho da funçäo ventricular é apresentda como campo importante para investigaçöes futuras.

Feocromocitoma: peculiaridades diagnósticas e terapêuticas / Pheochromocytoma. dicignostics and therapeutics peculiorities

O feocromocitoma é causa de hipertensão arterial (HA) na qual o tratamento cirúrgico oferece grande probabilidade de cura com normalização da pressão arterial. O presente relato de 5 casos de feocromocitoma com peculiaridades especiais tem como objetivo transmitir nossa experiência no diagnóstico e tratamento desta doença hipertensiva. Em 4 dos cinco casos observamos características pouco usuais da doença associada à neurofibromatose (1 caso), à valvopatia reumática (1 caso), a caráter maligno (1 caso) e à presença de alterações eletrocardiográficas indicativas de miocardite adrenérgica, revertidas após o tratamento cirúrgico (1 caso). Diante dos sintomas de hiperatividade adrenérgica presentes em todos os casos, a elevação dos níveis de ácido vanil-mandélico e metanefrinas urinárias foram úteis para a confirmação da suspeita clínica inicial. A associação da tomografia computadorizada e do mapeamento radioisotópico com metaiodobenzilguanidina (mIBG) permitiu a localização das massas tumorais, bem como das metástases ósseas de um caso de feocromocitoma maligno. Com o tratamento cirúrgico, após um período de 6 meses a 4 anos de evolução, quatro pacientes apresentaram cura da hipertensão, estavam assintomáticos e com normalização dos metabólitos urinários de catecolaminas. O doente, portador da forma maligna, permaneccu com produção elevada de catecolaminas, hipertenso após a retirada do tumor adrenal e realiza atualmente irradiação das metástases com mIBG radioativo

Pheochromocytoma is a cause of hypertension that frequently can be cured by surgery. The aim of this paper, based on 5 cases of pheochromocytoma, is to relate our experience in diagnosis and treatment in this pathology. In four of 5 patients with pheochromocytoma we observed unusual caracteristics of the disease. Association with neurofibromatosis in one case, with rheumatic mitral regurgitation in another; and in a third case the tumor was malignant. One patient had catechol amine-mediated electrocardiographic changes which disappeared with treatment. Since symptoms of adrenergic hiperactivity were present in all cases, the rise in the levels of vanilmandelic acid and urinary metanephrines were useful in confirming the diagnosis. Computed tomography and I-131 metabenzylquanidine for radioisotopic imaging, displayed not only all tumoral masses but also bone metastases in the malignant case. During the follow-up period, from the sixth month to the fourth year after surgery, four patients were asymptomatic, and have normal urinary catechoIAMine metabolite levels. The patient with a malignant form of pheochromocytoma continued to show elevated catecholamines release and remained hypertensive in spite of adrenal mass ressection

Associaçäo de lesöes arterioscleróticas e renais na hipertensäo arterial / Association of renal and arteriosclerotics lesions in arterial hypertension

Com o objetivo de estudar a prevalência e fatores implicados na associaçäo das lesöes arterioscleróticas das artérias coronárias e renais em hipertensos, foram analisados 73 pacientes com HA e suspeita clínica de insuficiência coronaria. A angiocoronariografia foi completada com arteriografia renal. Analisando comparativamente os pacientes com e sem arteriopatia renal concluiu-se que: a prevalência de lesöes arterioscleróticas renais em coronariopatias com HA é elevada (32%), sendo maior em hipertensos mais severos e com aumento da creatininemia. Os dados evolutivos sugerem pior prognóstico dos coronariopatas com doença renovascular associada

Avaliaçäo da funçäo renal e miocárdica na hipertensäo malígna / Evaluation of renal and myocardial functions in malignant hypertension

Foram avaliadas a funçäo renal e miocárdica em 13 pacientes com hipertensäo maligna (HM). Todos apresentavam hipertrofia miocárdica. A cintilografia renal revelou déficit de funçäo renal nos pacientes com creatininemia maior que 1,5mg%. A arteriografia mostrou lesäo severa em um caso, e lesöes de até 50% em quatro. Concluiu-se que a HM acomete órgäos-alvo de modo importante; existe correlaçäo entre cintilografia e creatininemia; a arteriografia está indicada pela alta prevalência de doença nevo-vascular e que o tratamento da HM parece deter a piora das lesöes em órgäos-alvo