Childhood cardiomyopathy

Cardiomyopathy in childhood is a rare and heterogeneous disease. The true prevalence is unknown; however, epidemiological studies from the United States, Australia, and Finland have reported an annual incidence of between 0.65 and 12.4 per 100,000. The most common type of cardiomyopathy in childhood is dilated cardiomyopathy followed by hypertrophic cardiomyopathy, while restrictive cardiomyopathy and other forms are much rarer (58.6% vs 25.5% vs 2.5% respectively). Although children may present at any age, the majority present under 1 year of age (63.4%).

Ethnicity and cardiovascular risk factors

Significant variation is evident among different ethnicities regarding the prevalence, awareness, severity, treatment, and complications of major cardiovascular disease (CVD) risk factors. Relative to white Europeans, stroke mortality is almost doubled in South Asians and Afro-Caribbeans; however, when coronary artery disease mortality is considered, it is high in South Asians and low in Afro-Caribbeans. Hypertension is more common, severe, and is associated with higher rates of morbidity and mortality in black people than white people. Diabetes is more prevalent and less controlled in South Asians which leads to a nearly fourfold higher cardiovascular mortality in South Asians than other ethnic groups. Furthermore, South Asians suffer from a highly atherogenic lipid profile. In contrast, black people are generally known for their higher high-density lipoprotein and lower triglyceride levels than white people which seem to play a major role in protecting them from coronary artery disease. For a given waist circumference, Asian, black, and Caucasian people show different levels of intra-abdominal adiposity and CVD risk. Hence, the joint definition from five major organizations in 2009 of the metabolic syndrome set ethnic-specific values of waist circumference to define central obesity. Black Caribbean men have the highest rates of current smoking among all ethnic groups in the United Kingdom while nearly all South Asian and black African women are never-smokers. Varied genetic and lifestyle-related risk factors and their interactions seem to be responsible for the ethnic differences in CVD risk factors. There is a clear need for ethnic-specific guidelines for diagnosis and treatment of major CVD risk factors to maximize the outcomes of preventive strategies.

Hypertensive disorders

Hypertensive disorders in pregnancy are the most common medical complications affecting 5–10% of pregnancies worldwide. This chapter discusses the following topics: diagnosis of hypertension, definition and classification of hypertension in pregnancy, additional laboratory tests, management of hypertension in pregnancy, pharmacological management of hypertension in pregnancy, delivery induction, blood pressure postpartum and lactation, and prognosis after pregnancy.

Aortic diseases

Aortic diseases encountered in young women are mainly associated with syndromic diseases, which are often heritable, or bicuspid aortic valve. The most frequent syndromic disease is Marfan syndrome. In Marfan syndrome, the risk of aortic dissection is low during pregnancy when the maximum diameter of the ascending aorta is less than 45 mm. Dissection may affect the thoracic ascending or descending aorta. The risk of aortic dissection is low in bicuspid aortic valve when the aortic diameter is less than 50 mm. Beta blockers are recommended throughout pregnancy in Marfan syndrome and are often used in other causes of aortic aneurysms. Close echocardiographic follow-up is needed during pregnancy and after delivery.

Diagnosis of acute pulmonary embolism and evolving imaging modalities

Modern non-invasive diagnostic strategies for pulmonary embolism rely on the sequential use of clinical probability assessment, D-dimer measurement, and thoracic imaging tests. Planar ventilation/perfusion scintigraphy was the cornerstone test for the diagnosis of pulmonary embolism for more than two decades and has now been replaced by computed tomographic pulmonary angiography (CTPA). Diagnostic strategies using CTPA are very safe to rule out pulmonary embolism and have been well validated in large prospective management outcome studies. Venous compression ultrasonography is the cornerstone test to diagnose deep vein thrombosis but is not mandatory for the diagnosis of pulmonary embolism when using multidetector CTPA.

Acute aortic syndrome: aortic dissection—ascending aortic dissection

Aortic dissection, intramural haematoma, and penetrating aortic ulcer can each present as an acute aortic syndrome. If left untreated, acute aortic syndrome carries a high mortality. Therefore, rapid diagnostic work-up and appropriate surgical therapy are of utmost importance. Chest computed tomography is the imaging method of first choice.

Referral centres and patient education

The need to engender high-quality clinical outcomes for a rare and lethal disease is best served by specialist referral centres with a high patient volume, although the volume–outcome relationship has not been shown specifically for pulmonary hypertension. The link between access to information and successful pulmonary arterial hypertension management is well established. Healthcare professionals report that patients who receive comprehensive guidance at the beginning of treatment have better outcomes. Information is understood to motivate patients to participate in their own care, thereby improving outcomes.

Screening for pulmonary arterial hypertension

Screening programmes for pulmonary hypertension are justifiable in some circumstances but not others. The inherent inaccuracies of the diagnostic tools and the low prevalence of pulmonary hypertension renders screening programmes ineffective unless the population evaluated with the primary screening tool (echocardiography) can be enriched. At the recent World Symposium of Pulmonary Hypertension screening programmes were recommended in asymptomatic systemic sclerosis, BMPR2 mutation carriers, patients with portal hypertension, and some groups with HIV, hereditary telangiectasis(HHT) or mutation carriers for HHT and congenital heart disease.

Device-based treatment for hypertension

Autonomic imbalance is thought to play an important role in the pathophysiology of hypertension. Despite the availability of diverse pharmacological options, non-adherence to medication or inability to tolerate current pharmacological therapies has led to the development of various device-based therapy options. Inhibiting components of the sympathetic nervous system offers a unique opportunity to target the ‘neural’ component of the neurohormonal axis. Combining novel drug-, device-, and procedure-based strategies with improved utilization of existing therapies (including appropriate attention to diet, exercise, and weight control) may result in improved outcomes. This chapter discusses the rationale and current experimental and clinical data of several novel device-based treatment options—renal nerve ablation, carotid body ablation, carotid baroreceptor stimulation, and central arteriovenous anastomosis.

Secondary prevention of sudden cardiac death in ischaemic cardiomyopathy

The most common reason for sudden cardiac death is ischaemic heart disease. Patients who survive cardiac arrest are at particularly high risk of recurrent ventricular arrhythmia and sudden cardiac death, and are candidates for secondary prevention defined as ‘therapies to reduce the risk of sudden cardiac death in patients who have already experienced an aborted cardiac arrest or life-threatening arrhythmias’. The mainstay therapy for secondary prevention of sudden cardiac death is implantation of an implantable cardioverter defibrillator. Furthermore, revascularization and optimal medical therapy for heart failure and concurrent cardiovascular diseases should be ensured.