Published online by Cambridge University Press: 05 June 2014
Introduction
Pulmonary hypertension is defined as a sustained mean pulmonary arterial pressure at rest of ≥ 25 mmHg, i.e., elevated significantly above the upper limit of normal (20 mmHg). Typically, pulmonary arterial pressure increases during exercise. In pulmonary hypertension, this increase is disproportionately high. The pressure is measured by right heart catheterization or can be estimated by echocardiography.
Pulmonary hypertension is a consequence of right ventricular adaptation to increased vascular resistance, increased pulmonary blood flow, or a combination of both. Initially, the symptoms of pulmonary hypertension are nonspecific and usually limited to dyspnea, particularly on exertion, or patients may be asymptomatic. As the pulmonary hypertension progresses, signs and symptoms of right-sided heart failure develop; namely peripheral edema, fatigue, abdominal fullness, angina pectoris and syncope. Depending on its cause, severity and possible treatment options, pulmonary hypertension may lead to death.
Pulmonary hypertension is a feature of a heterogeneous group of disorders which differ in risk factor profile, initiating factors, response to treatment and prognosis (Table 1).4,5 Among the causal factors, left ventricular failure and mitral valve insufficiency are the commonest, followed by chronic thromboembolic disease.6 Globally, there are marked variations in prevalence of some important causes and risk factors, especially sickle cell disease, chronic schistosomiasis and HIV-AIDS.
To save this book to your Kindle, first ensure no-reply@cambridge-org.demo.remotlog.com is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.