Biventricular structural and functional responses to aortic constriction in a rabbit model of chronic right ventricular pressure overload

Objectives: Chronic right ventricular (RV) pressure overload results in pathologic RV hypertrophy and diminished RV function. Although aortic constriction has been shown to improve systolic function in acute RV failure, its effect on RV responses to chronic pressure overload is unknown. Methods: Adjustable vascular banding devices were placed on the main pulmonary artery and descending aorta. In 5 animals (sham group), neither band was inflated. In 9 animals (PAB group), only the pulmonary arterial band was inflated, with adjustments on a weekly basis to generate systemic or suprasystemic RV pressure at 28 days. In 9 animals, both pulmonary arterial and aortic devices were inflated (PAB+AO group), the pulmonary arterial band as for the PAB group and the aortic band adjusted to increase proximal systolic blood pressure by approximately 20 mm Hg. Effects on the functional performance were assessed 5 weeks after surgery by conductance catheters, followed by histologic and molecular assessment. Results: Contractile performance was significantly improved in the PAB+AO group versus the PAB group for both ventricles. Relative to sham-operated animals, both banding groups showed significant differences in myocardial histologic and molecular responses. Relative to the PAB group, the PAB+AO group showed significantly decreased RV cardiomyocyte diameter, decreased RV collagen content, and reduced RV expression of endothelin receptor type B, matrix metalloproteinase 9, and transforming growth factor beta genes. Conclusions: Aortic constriction in an experimental model of chronic RV pressure overload not only resulted in improved biventricular systolic function but also improved myocardial remodeling. These data suggest that chronically increased left ventricular afterload leads to a more physiologically hypertrophic response in the pressure-overloaded RV. (J Thorac Cardiovasc Surg 2012;144:1494-501)

Estudo do Padrão Respiratório e Movimento Toracoabdominal em Valvopatia Mitral

FUNDAMENTO: pacientes com valvopatia mitral podem evoluir com congestão pulmonar, que aumenta o trabalho dos músculos respiratórios; essa sobrecarga pode alterar o padrão respiratório com predomínio do deslocamento torácico ou presença de movimentos paradoxais. OBJETIVO: a) estudar o padrão respiratório e movimento toracoabdominal (MTA) em pacientes com doença mitral b) estudar o efeito do posicionamento nos parâmetros respiratórios c) correlacionar hipertensão pulmonar com presença de incoordenação do MTA. MÉTODOS: o padrão respiratório e o MTA de pacientes com doença mitral foram avaliados por pletismografia respiratória por indutância, nas posições dorsal e sentada, durante dois minutos de respiração tranquila. Analisou-se volume corrente (Vc) e tempos respiratórios e as variáveis do MTA. RESULTADOS: de 65 pacientes incluídos, 10 foram retirados, 29 participaram do grupo estenose mitral e 26 do grupo insuficiência mitral. O Vc, a ventilação pulmonar e o fluxo inspiratório médio aumentaram significantemente na posição sentada, sem diferenças entre os grupos. O MTA manteve-se coordenado entre os grupos e as posições; no entanto, cinco pacientes na posição dorsal apresentaram incoordenação (três no grupo estenose mitral; dois no grupo insuficiência mitral) com correlação significante com valores de pressão de artéria pulmonar (r = 0,992, p = 0,007). CONCLUSÃO: o padrão respiratório e o MTA não apresentam diferenças entre pacientes com estenose ou insuficiência mitral. A posição sentada aumenta o Vc sem alterar os tempos respiratórios. A presença de incoordenação toracoabdominal na posição dorsal esteve associação à hipertensão pulmonar.

A randomized controlled trial of fetal endoscopic tracheal occlusion versus postnatal management of severe isolated congenital diaphragmatic hernia

Objective Severe pulmonary hypoplasia and pulmonary arterial hypertension are associated with reduced survival in congenital diaphragmatic hernia (CDH). We aimed to determine whether fetal endoscopic tracheal occlusion (FETO) improves survival in cases of severe isolated CDH. Methods Between May 2008 and July 2010, patients whose fetuses had severe isolated CDH (lung-to-head ratio < 1.0, liver herniation into the thoracic cavity and no other detectable anomalies) were assigned randomly to FETO or to no fetal intervention (controls). FETO was performed under maternal epidural anesthesia supplemented with fetal intramuscular anesthesia. Tracheal balloon placement was achieved with ultrasound guidance and fetoscopy between 26 and 30 weeks of gestation. All cases that underwent FETO were delivered by the EXIT procedure. Postnatal therapy was the same for both treated fetuses and controls. The primary outcome was survival to 6 months of age. Other maternal and neonatal outcomes were also evaluated. Results Twenty patients were enrolled randomly to FETO and 21 patients to standard postnatal management. The mean gestational age at randomization was similar in both groups (P = 0.83). Delivery occurred at 35.6 +/- 2.4 weeks in the FETO group and at 37.4 +/- 1.9 weeks in the controls (P < 0.01). In the intention-to-treat analysis, 10/20 (50.0%) infants in the FETO group survived, while 1/21 (4.8%) controls survived (relative risk (RR), 10.5 (95% CI, 1.5-74.7), P < 0.01). In the receivedtreatment analysis, 10/19 (52.6%) infants in the FETO group and 1/19 (5.3%) controls survived (RR, 10.0 (95% CI, 1.4-70.6) P < 0.01). Conclusion FETO improves neonatal survival in cases with isolated severe CDH. Copyright (C) 2011 ISUOG. Published by John Wiley & Sons, Ltd.

Hand-carried ultrasound performed at bedside in cardiology inpatient setting – a comparative study with comprehensive echocardiography

Abstract Background Hand-carried ultrasound (HCU) devices have been demonstrated to improve the diagnosis of cardiac diseases over physical examination, and have the potential to broaden the versatility in ultrasound application. The role of these devices in the assessment of hospitalized patients is not completely established. In this study we sought to perform a direct comparison between bedside evaluation using HCU and comprehensive echocardiography (CE), in cardiology inpatient setting. Methods We studied 44 consecutive patients (mean age 54 ± 18 years, 25 men) who underwent bedside echocardiography using HCU and CE. HCU was performed by a cardiologist with level-2 training in the performance and interpretation of echocardiography, using two-dimensional imaging, color Doppler, and simple calliper measurements. CE was performed by an experienced echocardiographer (level-3 training) and considered as the gold standard. Results There were no significant differences in cardiac chamber dimensions and left ventricular ejection fraction determined by the two techniques. The agreement between HCU and CE for the detection of segmental wall motion abnormalities was 83% (Kappa = 0.58). There was good agreement for detecting significant mitral valve regurgitation (Kappa = 0.85), aortic regurgitation (kappa = 0.89), and tricuspid regurgitation (Kappa = 0.74). A complete evaluation of patients with stenotic and prosthetic dysfunctional valves, as well as pulmonary hypertension, was not possible using HCU due to its technical limitations in determining hemodynamic parameters. Conclusion Bedside evaluation using HCU is helpful for assessing cardiac chamber dimensions, left ventricular global and segmental function, and significant valvular regurgitation. However, it has limitations regarding hemodynamic assessment, an important issue in the cardiology inpatient setting.

Echocardiographic and hemodynamic determinants of right coronary artery flow reserve and phasic flow pattern in advanced non-ischemic cardiomyopathy

Abstract Background In patients with advanced non-ischemic cardiomyopathy (NIC), right-sided cardiac disturbances has prognostic implications. Right coronary artery (RCA) flow pattern and flow reserve (CFR) are not well known in this setting. The purpose of this study was to assess, in human advanced NIC, the RCA phasic flow pattern and CFR, also under right-sided cardiac disturbances, and compare with left coronary circulation. As well as to investigate any correlation between the cardiac structural, mechanical and hemodynamic parameters with RCA phasic flow pattern or CFR. Methods Twenty four patients with dilated severe NIC were evaluated non-invasively, even by echocardiography, and also by cardiac catheterization, inclusive with Swan-Ganz catheter. Intracoronary Doppler (Flowire) data was obtained in RCA and left anterior descendent coronary artery (LAD) before and after adenosine. Resting RCA phasic pattern (diastolic/systolic) was compared between subgroups with and without pulmonary hypertension, and with and without right ventricular (RV) dysfunction; and also with LAD. RCA-CFR was compared with LAD, as well as in those subgroups. Pearson's correlation analysis was accomplished among echocardiographic (including LV fractional shortening, mass index, end systolic wall stress) more hemodynamic parameters with RCA phasic flow pattern or RCA-CFR. Results LV fractional shortening and end diastolic diameter were 15.3 ± 3.5 % and 69.4 ± 12.2 mm. Resting RCA phasic pattern had no difference comparing subgroups with vs. without pulmonary hypertension (1.45 vs. 1.29, p = NS) either with vs. without RV dysfunction (1.47 vs. 1.23, p = NS); RCA vs. LAD was 1.35 vs. 2.85 (p < 0.001). It had no significant correlation among any cardiac mechanical or hemodynamic parameter with RCA-CFR or RCA flow pattern. RCA-CFR had no difference compared with LAD (3.38 vs. 3.34, p = NS), as well as in pulmonary hypertension (3.09 vs. 3.10, p = NS) either in RV dysfunction (3.06 vs. 3.22, p = NS) subgroups. Conclusion In patients with chronic advanced NIC, RCA phasic flow pattern has a mild diastolic predominance, less marked than in LAD, with no effects from pulmonary artery hypertension or RV dysfunction. There is no significant correlation between any cardiac mechanical-structural or hemodynamic parameter with RCA-CFR or RCA phasic flow pattern. RCA flow reserve is still similar to LAD, independently of those right-sided cardiac disturbances.

Sildenafil vs. Nitroprussiato de Sódio durante Teste de Reatividade Pulmonar pré-transplante cardíaco

FUNDAMENTO: A hipertensão pulmonar é associada ao pior prognóstico no pós-transplante cardíaco. O teste de reatividade pulmonar com Nitroprussiato de Sódio (NPS) está associado a elevados índices de hipotensão arterial sistêmica, disfunção ventricular do enxerto transplantado e elevadas taxas de desqualificação para o transplante. OBJETIVO: Neste estudo, objetivou-se comparar os efeitos do Sildenafil (SIL) e NPS sobre variáveis hemodinâmicas, neuro-hormonais e ecocardiográficas durante teste de reatividade pulmonar. MÉTODOS: Os pacientes foram submetidos, simultaneamente, ao cateterismo cardíaco direito, ao ecocardiograma e à dosagem de BNP e gasometria venosa, antes e após administração de NPS (1 - 2 µg/Kg/min) ou SIL (100 mg, dose única). RESULTADOS: Ambos reduziram a hipertensão pulmonar, porém o nitrato promoveu hipotensão sistêmica significativa (Pressão Arterial Média - PAM: 85,2 vs. 69,8 mmHg, p < 0,001). Ambos reduziram as dimensões cardíacas e melhoraram a função cardíaca esquerda (NPS: 23,5 vs. 24,8 %, p = 0,02; SIL: 23,8 vs. 26 %, p < 0,001) e direita (SIL: 6,57 ± 2,08 vs. 8,11 ± 1,81 cm/s, p = 0,002; NPS: 6,64 ± 1,51 vs. 7,72 ± 1,44 cm/s, p = 0,003), medidas pela fração de ejeção ventricular esquerda e Doppler tecidual, respectivamente. O SIL, ao contrário do NPS, apresentou melhora no índice de saturação venosa de oxigênio, medido pela gasometria venosa. CONCLUSÃO: Sildenafil e NPS são vasodilatadores que reduzem, de forma significativa, a hipertensão pulmonar e a geometria cardíaca, além de melhorar a função biventricular. O NPS, ao contrário do SIL, esteve associado a hipotensão arterial sistêmica e piora da saturação venosa de oxigênio.

Ausência de estreita associação entre qualidade de vida e capacidade de exercício na hipertensão arterial pulmonar

FUNDAMENTO: Na hipertensão arterial pulmonar (HAP) a qualidade de vida relacionada saúde (QVRS) tem sido investigada em curtos períodos de tempo (semanas), mas pouco se sabe sobre a perspectiva do paciente no médio e longo prazo. OBJETIVO: Analisar o estado de pacientes em terapias específicas de HAP durante um ano de observação, em termos de QVRS, e investigar se possíveis associações entre a capacidade de exercício (CE) e a QVRS persistem no médio prazo. MÉTODOS: Trinta e quatro pacientes em terapias para a HAP (bosentan e/ou sildenafil) foram selecionados (idade de 14 a 58 anos, mediana de 35,5 anos, classe funcional II ou III), e avaliados no momento basal, e 3, 6, 9 e 12 meses depois, usando o teste de caminhada de 6 minutos e questionário SF-36 de QVRS. RESULTADOS: A distância percorrida nos seis minutos não mudou durante o acompanhamento (387 - 432 metros, valores da mediana, p=0.2775), o mesmo para a classe funcional e saturação periférica de oxigênio. Os escores SF-36 também se mantiveram estáveis, com a saúde física sempre pior que a saúde mental. Das 40 possíveis associações entre a CE e QVRS, apenas 12 foram significativas (30%, p<0,05). A previsão de uma QVRS severamente deprimida com base em uma distância percorrida de 235 metros foi específica em >90%, mas sensível em <43%. CONCLUSÃO: Os pacientes com HAP que se mantêm estáveis em termos da CE também parecem fazê-lo em termos de QVRS. Contudo, CE e QVRS não têm ligação consistente com o tempo, e devem ser analisadas como diferentes perspectivas no paciente individual.

Utilzzo dei parametri ecocardiografici tradizionali ed a Doppler tissutale nella valutazione della disfunzione atrio-ventricolare in cani affetti da malattia mitralica cronica

In questo lavoro ci siamo posti come obiettivo lo studio della disfunzione atrio-ventricolare mediante tecniche ecocardiografiche avanzate (come il Tissue Doppler Imaging - TDI) in cani affetti da malattia mitralica cronica (MVD). Una prima parte è volta alla valutazione della funzionalità diastolica del ventricolo destro. Ci siamo proposti di analizzare la funzione del ventricolo destro in cani affetti da malattia del cuore sinistro per comprendere se quest’ultima possa condizionare direttamente la performance del settore cardiaco controlaterale. I risultati più importanti che abbiamo riscontrato sono: l’assenza di differenze significative nella disfunzione sisto-diastolica del ventricolo destro in cani con MVD a diverso stadio; la diretta correlazione tra le variabili TDI di funzionalità del ventricolo destro con il grado di disfunzione del ventricolo sinistro, come indicatori di interdipendenza ventricolare; ed infine il riscontro di una maggior tendenza ad alterazioni diastoliche del ventricolo sinistro in cani con ipertensione polmonare. A quest’ultimo proposito, per quanto riguarda le variabili TDI, il rapporto E/e’ dell’anulus mitralico laterale e settale è risultato avere una differenza significativa tra i cani con ipertensione polmonare e quelli privi di ipertensione polmonare (P<0,01). Nel secondo studio abbiamo applicato il TDI per l’analisi della funzione sisto-diastolica dell’atrio sinistro. Il lavoro è stato articolato in una parte di validazione della metodica su cani normali ed una su animali affetti da MDV. I risultati ottenuti mostrano che la valutazione ecocardiografica delle proprietà di deformazione dell’atrio sinistro basata sul TDI è attuabile e riproducibile nel cane. Abbiamo fornito dei valori di normalità per questa specie e confrontato questi dati con quelli ricavati in cani portatori di MVD. Le differenza tra le varie classi di malattia, nei diversi gradi di dilatazione atriale, sono risultate limitate, ma abbiamo individuato delle correlazioni tra i parametri TDI ed alcune variabili di funzionalità atriale.

High altitude, a natural research laboratory for the study of cardiovascular physiology and pathophysiology

High altitude constitutes an exciting natural laboratory for medical research. Although initially, the aim of high-altitude research was to understand the adaption of the organism to hypoxia and find treatments for altitude-related diseases, during the past decade or so, the scope of this research has broadened considerably. Two important observations led the foundation for the broadening of the scientific scope of high-altitude research. First, high-altitude pulmonary edema represents a unique model that allows studying fundamental mechanisms of pulmonary hypertension and lung edema in humans. Second, the ambient hypoxia associated with high-altitude exposure facilitates the detection of pulmonary and systemic vascular dysfunction at an early stage. Here, we will review studies that, by capitalizing on these observations, have led to the description of novel mechanisms underpinning lung edema and pulmonary hypertension and to the first direct demonstration of fetal programming of vascular dysfunction in humans.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: executive summary

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure, and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death.Medical aspects that need to be considered relate to the long-term and multisystemic effects of single-ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the understanding of the late outcomes, genetics, medical therapy and interventional approaches in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. The present executive summary is a brief overview of the new guidelines and includes the recommendations for interventions. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology, including sections on genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy and contraception risks, and follow-up requirements. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Adverse cardiac events during catecholamine vasopressor therapy: a prospective observational study

PURPOSE: To determine the incidence of and risk factors for adverse cardiac events during catecholamine vasopressor therapy in surgical intensive care unit patients with cardiovascular failure. METHODS: The occurrence of any of seven predefined adverse cardiac events (prolonged elevated heart rate, tachyarrhythmia, myocardial cell damage, acute cardiac arrest or death, pulmonary hypertension-induced right heart dysfunction, reduction of systemic blood flow) was prospectively recorded during catecholamine vasopressor therapy lasting at least 12 h. RESULTS: Fifty-four of 112 study patients developed a total of 114 adverse cardiac events, an incidence of 48.2 % (95 % CI, 38.8-57.6 %). New-onset tachyarrhythmia (49.1 %), prolonged elevated heart rate (23.7 %), and myocardial cell damage (17.5 %) occurred most frequently. Aside from chronic liver diseases, factors independently associated with the occurrence of adverse cardiac events included need for renal replacement therapy, disease severity (assessed by the Simplified Acute Physiology Score II), number of catecholamine vasopressors (OR, 1.73; 95 % CI, 1.08-2.77; p = 0.02) and duration of catecholamine vasopressor therapy (OR, 1.01; 95 % CI, 1-1.01; p = 0.002). Patients developing adverse cardiac events were on catecholamine vasopressors (p < 0.001) and mechanical ventilation (p < 0.001) for longer and had longer intensive care unit stays (p < 0.001) and greater mortality (25.9 vs. 1.7 %; p < 0.001) than patients who did not. CONCLUSIONS: Adverse cardiac events occurred in 48.2 % of surgical intensive care unit patients with cardiovascular failure and were related to morbidity and mortality. The extent and duration of catecholamine vasopressor therapy were independently associated with and may contribute to the pathogenesis of adverse cardiac events.

[Needle in the haystack - potentially dangerous syncope in childhood]

Syncope is a frequently observed symptom in pediatrics with teenagers being the age group most often affected. In contrast to older age, organic cardiac causes of syncope in child-hood are observed in a minority of only 2-5% of cases, in their majority pediatric syncopes thus are neurocardiogenic in origin. The rare organic cardiac causes that may manifest with syncope are all potentially dangerous entities such as cardiomyopathies, genetic primary electrical disease and some forms of structural heart disease, as well as some other rare diseases such as e.g. primary pulmonary hypertension. These diseases have to be actively looked for or excluded. Guidelines recommend patient evaluation including history, physical examination and ECG, which is sufficient to sort out suspect cases after a syncopal episode.

[Fetal programming of cardiovascular disease: new causes and underlying mechanisms]

There exists an association between pathologic events occurring during early life and the development of cardiovascular disease in adulthood. For example, transient perinatal hypoxemia predisposes to exaggerated hypoxic pulmonary hypertension and preeclampsia predisposes the offspring to pulmonary and systemic endothelial dysfunction later in life. The latter finding offers a scientific basis for observations demonstrating an increased risk for premature cardiovascular morbidity in this population. Very recently, we showed that offspring of assisted reproductive technologies also display generalized vascular dysfunction and early arteriosclerosis. Studies in animal models have provided evidence that oxidative stress and/or epigenetic alterations play an important pathophysiological role in the fetal programming of cardiovascular disease.