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 ï Migraine ï Dizziness ï Panic attacks ï Low blood pressure when lying down ï Shortness of breath ï Palpitations ï 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.
Treatment: Individuals with mitral valve prolapse, particularly those without symptoms, often require no treatment. Those with mitral valve prolapse and symptoms of dysautonomia (palpitations, chest pain) may benefit from beta-blockers (e.g., propranolol). Patients with prior stroke and/or atrial fibrillation may require blood thinners, such as aspirin or warfarin. In rare instances when mitral valve prolapse is associated with severe mitral regurgitation, mitral valve repair or surgical replacement may be necessary. Mitral valve repair is generally considered preferable to replacement. Current ACC/AHA guidelines promote repair of mitral valve in patients before symptoms of heart failure develop. Symptomatic patients, those with evidence of diminished left ventricular function, or those with left ventricular dilatation need urgent attention.
Statistics: During 2009–2010, the total number of reported cases of giardiasis increased slightly from 19,403 for 2009 to 19,888 for 2010. During this period, 50 jurisdictions reported giardiasis cases. A larger number of case reports were received for children aged 1–9 years than with other age groups. The number of cases peaked annually during early summer through early fall. During 2009–2010, the total number of reported cases of giardiasis increased 1.9%, from 19,562 for 2009 to 19,927 for 2010. During this period, 50 jurisdictions (46 states, two cities (DC and NYC), Puerto Rico, and Guam) reported giardiasis cases. Giardiasis rates in the United States remained relatively stable at 7.3–7.6 cases per 100,000 population. For 2010, among reported cases, the rate of giardiasis per 100,000 population ranged from 2.6 in Arizona to 29.6 in Vermont. Vermont reported the highest rate for both years of the reporting period, at 35.4 in 2009 and 29.6 in 2010. The Midwest region reported the highest rate of giardiasis in 2010 at 11.4 per 100,000 population, followed by the Northwest at 10.3 Most cases for which data on race were available for 2009–2010 occurred among whites, followed by blacks, Asians/Pacific Islanders, and American Indians/Alaska Natives. However, data on race were not included for 41.9%–43.7% of total cases reported annually. Although 6.9%–9.6% of patients were identified as Hispanic, data on ethnicity were lacking for 48.9% of total annual case reports. A twofold increase in reported giardiasis cases occurred during the peak month of reporting in August compared with the lowest month, December. The increased number of cases began in mid-May, peaked in August, and declined through September. Among all jurisdictions that reported cases of giardiasis, the rate has declined from 13.8 to 7.6 (45%) since the peak in case reporting in 1995. Since 2002, when giardiasis became nationally notifiable, the incidence rates have remained relatively stable, ranging from 8.7–7.2