Barlow syndrome is mitral valve prolapse (also known as "click murmur syndrome"), the most common heart valve abnormality, affecting 5-10% of the world population. Most patients have no symptoms and require no treatment. However, the condition can be associated with fatigue and/or palpitations. The mitral valve prolapse can often be detected by a doctor during examination of the heart and can be confirmed with anechocardiogram. Patients are usually given antibiotics prior to any procedure which might introduce bacteria into the bloodstream, including dental work and minor surgery.
Causes: The underlying problem with the valve is a degeneration of the tissue causing the leaflets to become stretched and enlarged. This redundant tissue bulges into the atrium, preventing the valve from closing properly. The exact reason for this tissue change is not known, but it is associated with the tissue degenerative disorders. Functional MVP can occur with completely normal valve leaflets: this is found in conditions of abnormal papillary muscle function due to myocardial ischaemia, and in dilated cardiomyopathy. Patients with hypertrophic cardiomyopathy are also at risk.
Symptoms: Most patients do not experience symptoms. However, when they do the symptoms include: Fatigue, Migraine, Dizziness, Panic attacks, Low blood pressure when lying down, Shortness of breath, Palpitations, Chest pain that is not angina However, these non-specific symptoms are not reliable indicators of the condition. When the doctor listens to the heart, a murmur may be heard. This is caused by irregular blood flow through the valve. A click may also be heard, thought to be due to the snapping of the anchoring “ropes” – the chordea – as the valve billows and then is suddenly held taut. This is much like the snapping taut of the sails on a boat. These sounds are often transient or absent, and might only be detected by an experienced cardiologist. If there are problems with the function of the left ventricle, the patient may experience shortness of breath and troublesome irregularities of heart rhythm. Barlow’s syndrome may result in severe dysfunction of the mitral valve, leading to what is called mitral regurgitation (MR), a leaking, or incompetent valve. Mitral regurgitation means that blood flows back into the left atrium during contraction rather than moving forwards into the aorta as it should do. About 25% of people with Barlow's syndrome also suffer from lax joints, and a high arched palate in the mouth (these patients may also have a degree of Marfan's syndrome), and other abnormalities of their skeleton such as scoliosis, a funnel chest and a straight back.
Statistics: Overall in the study population, zero, 1, 2 and ≥3 (i.e., metabolic syndrome) risk factors for MS were observed in 29% (n = 129), 26% (n = 118), 22% (n = 98) and 23% (n = 104) men, respectively. The mean METS achieved in the study population was 10 ± 2 (range 4–20). Nearly half (49%) of individuals with the highest levels of CRF had no MS risk factors whereas only 18% of those with low CRF (METS <9) had no MS risk factors. On the other end of the spectrum, the prevalence of MS (≥3 MS risk factors) increased significantly across decreasing levels of CRF (6, 22, 33% p <0.0001 for trend). Multivariable polytomous logistic regression (adjusting for age, smoking, cholesterol-lowering therapy) demonstrated that individuals with low CRF (1st tertile of METS) compared to those with highest CRF had 3.1- (p = 0.001) and 11.8- (p <0.0001) fold higher risk of having 2 and ≥3 MS components, respectively. Similar results were observed when the analyses was repeated adjusting for Framingham risk score. RLS was found in 27% of patients. Poor sleep quality was present in 45% of cases and was associated with age (P = 0.04), peripheral neuropathy (P = 0.001), and RLS (P = 0.000). EDS was found in 26% of patients. Logistic regression analysis revealed an association between RLS and peripheral neuropathy (odds ratio 12.85 [95% CI 2.83–58.40], P = 0.001).