Cirrhotic Cardiomyopathy - A Veiled Threat

Cirrhotic cardiomyopathy (CCM) is defined as cardiac dysfunction in patients with liver cirrhosis without pre-existing cardiac disease. According to the definition established by the World Congress of Gasteroenterology in 2005, the diagnosis of CCM includes criteria reflecting systolic dysfunction, impaired diastolic relaxation, and electrophysiological disturbances. Because of minimal or even absent clinical symptoms and/or echocardiographic signs at rest according to the 2005 criteria, CCM diagnosis is often missed or delayed in most clinically-stable cirrhotic patients. However, cardiac dysfunction progresses in time and contributes to the pathogenesis of hepatorenal syndrome and increased morbidity and mortality after liver transplantation, surgery or other invasive procedures in cirrhotic patients. Therefore, a comprehensive cardiovascular assessment using newer techniques for echocardiographic evaluation of systolic and diastolic function, allowing the diagnosis of CCM in the early stage of subclinical cardiovascular dysfunction, should be included in the screening process of liver transplant candidates and patients with cirrhosis in general. The present review aims to summarize the most important pathophysiological aspects of CCM, the usefulness of contemporary cardiovascular imaging techniques and parameters in the diagnosis of CCM, the current therapeutic options, and the importance of early diagnosis of cardiovascular impairment in cirrhotic patients.

Cardiovascular dysfunction and liver transplantation

Cardiovascular complications have emerged as the leading cause of death after liver transplantation, particularly among those with advanced liver cirrhosis. Therefore, a thorough and accurate cardiovascular evaluation with clear comprehension of cirrhotic cardiomyopathy is recommended for optimal anesthetic management. However, cirrhotic patients manifest cardiac dysfunction concomitant with pronounced systemic hemodynamic changes, characterized by hyperdynamic circulation such as increased cardiac output, high heart rate, and decreased systemic vascular resistance. These unique features mask significant manifestations of cardiac dysfunction at rest, which makes it difficult to accurately evaluate cardiovascular status. In this review, we have summarized the current knowledge of heart and liver interactions, focusing on the usefulness and limitations of cardiac evaluation tools for identifying high-risk patients.

Cirrhotic Multiorgan Syndrome

Patients with cirrhosis and portal hypertension are at an increased risk of the development of circulatory dysfunction that may potentially result in multiple organ failure. Apart from the liver, this may involve the heart, lungs, kidneys, the immune system, the adrenal glands, and other organ systems. As the disease progresses, the circulation becomes hyperdynamic, and signs of cardiac, pulmonary, and renal dysfunction are observed, in addition to reduced survival. Infections and an altered cardiac function known as cirrhotic cardiomyopathy may be precipitators for the development of other complications such as hepatorenal syndrome. In patients with chronic organ dysfunction, various precipitating events may induce an acute-on-chronic renal failure and acute-on-chronic liver failure that negatively affect the prognosis. Future research on the pathophysiologic mechanisms of the complications and the precipitating factors is essential to understand the basics of the treatment of these challenging conditions. The aim of the present review is to focus on the development and precipitating factors of various organ failures in patients with decompensated cirrhosis.

Cirrhotic cardiomyopathy: pathogenesis and clinical relevance

Cirrhosis is known to cause alterations in the systemic haemodynamic system. Cirrhotic cardiomyopathy designates a cardiac dysfunction that includes impaired cardiac contractility with systolic and diastolic dysfunction, as well as electromechanical abnormalities in the absence of other known causes of cardiac disease. This condition is primarily revealed by inducing physical or pharmacological stress, but echocardiography is excellent at revealing diastolic dysfunction and might also be used to detect systolic dysfunction at rest. Furthermore, measurement of circulating levels of cardiac biomarkers could improve the diagnostic assessm+ent. Cirrhotic cardiomyopathy contributes to various complications in cirrhosis, especially as an important factor in the development of hepatic nephropathy. Additionally, cirrhotic cardiomyopathy seems to be associated with the development of heart failure in relation to invasive procedures such as shunt insertion and liver transplantation. Current pharmacological treatment is nonspecific and directed towards left ventricular failure, and liver transplantation is currently the only proven treatment with specific effect on cirrhotic cardiomyopathy.

Vitamin C prevents intrauterine programming of in vivo cardiovascular dysfunction in the rat

BACKGROUND

Fetal hypoxia is common and in vitro evidence supports its role in the programming of adult cardiovascular dysfunction through the generation of oxidative stress. Whether fetal chronic hypoxia programmes alterations in cardiovascular control in vivo, and if these alterations can be prevented by antioxidant treatment, is unknown. This study investigated the effects of prenatal fetal hypoxia, with and without maternal supplementation with vitamin C, on basal and stimulated cardiovascular function in vivo in the adult offspring at 4 months of age in the rat.

METHODS AND RESULTS

From days 6 to 20 of pregnancy, Wistar rats were subjected to Normoxia, Hypoxia (13% O2), Hypoxia+Vitamin C (5mg/ml in drinking water) or Normoxia+Vitamin C. At 4 months, male offspring were instrumented under urethane anaesthesia. Basal mean arterial blood pressure, heart rate and heart rate variability (HRV) were assessed, and stimulated baroreflex curves were generated with phenylephrine and sodium nitroprusside. Chronic fetal hypoxia increased the LF/HF HRV ratio and baroreflex gain, effects prevented by vitamin C administration during pregnancy.

CONCLUSIONS

Chronic intrauterine hypoxia programmes cardiovascular dysfunction in vivo in adult rat offspring; effects ameliorated by maternal treatment with vitamin C. The data support a role for fetal chronic hypoxia programming cardiovascular dysfunction in the adult rat offspring in vivo through the generation of oxidative stress in utero.