Rapid Heartbeat and Dizziness: Cardiovascular Insights - Cardiology

Dr. He Dongjin reply Cardiology

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Dear Enjoy, the symptoms you described are known as palpitations, which may be related to endocrine issues or mitral valve prolapse.
Medication can effectively improve these symptoms.

Mitral valve prolapse (MVP) refers to a condition where the mitral valve, located between the left atrium and left ventricle of the heart, does not close properly.
To understand this, we first need to know the structure of the heart, which consists of four chambers: the left and right atria and the left and right ventricles.
Valves separate the atria from the ventricles, functioning like doors that allow blood to flow in one direction, preventing backflow.

The mitral valve, also known as the bicuspid valve due to its resemblance to a bishop's miter, opens during diastole to allow blood flow from the left atrium into the left ventricle.
When the left ventricle fills with blood and enters systole, the mitral valve closes automatically, enabling blood to be pumped into the aorta and circulated throughout the body without flowing back into the left atrium.
Mitral valve prolapse occurs when congenital or acquired factors cause the annulus (the valve's supporting structure) to enlarge, making the valve relatively smaller and unable to close tightly, leading to part of the valve drooping into the left atrium.
It can also result from degenerative changes in the valve tissue or elongation of the valve leaflets, causing some of the valve to be pushed back into the left atrium during closure, which is termed mitral valve prolapse.
Statistics indicate that approximately 5-10% of the population has mitral valve prolapse, with its etiology largely unknown but mostly related to genetic factors.
It is more common in females than males, with a ratio of about 3:1.
Most patients are asymptomatic and discover their condition during routine examinations or evaluations for other health issues.
Those who do experience symptoms typically present with at least two of the following: chest pain, palpitations, fatigue, shortness of breath, dizziness, insomnia, anxiety, panic attacks, or even syncope.
These symptoms are not directly caused by heart issues but are due to excessive sympathetic nervous system activity, leading to what is sometimes referred to as autonomic dysregulation syndrome.

Mitral valve prolapse is essentially another manifestation of this syndrome and does not have a causal relationship with other symptoms.
Some patients may experience mitral regurgitation due to the valve's inability to close properly, resulting in backward blood flow into the left atrium during ventricular contraction.
This condition can lead to left atrial enlargement and may increase the risk of young-onset stroke, infective endocarditis, or even sudden death, warranting caution.
Diagnosis of mitral valve prolapse can be made through clinical auscultation, where characteristic clicks or murmurs may be heard.
However, electrocardiograms and chest X-rays are not particularly diagnostic.
The most important examination is echocardiography, which can visualize the prolapse and assess for mitral regurgitation or other related conditions such as rheumatic heart disease or ischemic heart disease.
The frequency, timing, triggers, and severity of symptoms can vary widely among individuals.
Some may experience episodes weekly, while others may go months or even years without symptoms.
Triggers can include colds, menstruation, emotional stress, lack of sleep, delayed meals, excessive fatigue, engaging in unfamiliar physical activities, prolonged exposure to dry and hot environments, dehydration from excessive sweating, or the use of stimulants such as tobacco, alcohol, caffeine, or drugs.

Most patients can tolerate these symptoms, but a small subset may find them debilitating, leading to frequent emergency room visits and significant disruption to their lives, sometimes resulting in a crisis.
There are instances where patients with severe chest pain are misdiagnosed with angina and undergo cardiac catheterization, but fatalities due to life-threatening complications are rare.
Medications can only provide symptomatic relief and do not cure mitral valve prolapse.
Surgical intervention is typically reserved for cases with significant mitral regurgitation affecting cardiac function or for those with infective endocarditis, and it does not alleviate the aforementioned symptoms.
Fortunately, the number of cases requiring surgery is quite low, and most patients can achieve some degree of symptom relief through medication.

Patients should also come to terms with living with this condition as an invisible defect in their body.
If individuals suspect they have mitral valve prolapse based on the symptoms described, they should consult a cardiologist for evaluation.
If echocardiography confirms the diagnosis, patients should be aware of situations that may trigger their symptoms and actively avoid them.
With appropriate medication prescribed by their physician, most symptoms can be well-controlled.

If moderate or severe mitral regurgitation is present, patients should inform their physician about the need for prophylactic antibiotics during invasive procedures or dental extractions to reduce the risk of infective endocarditis.
Unless there is significant regurgitation affecting cardiac function, the vast majority of patients can have children.
As for exercise, opinions vary on its safety.
If symptoms arise during physical activity, patients should consult their cardiologist to evaluate what types of exercise are appropriate.

Changhua Hospital cares about your health.

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Reply Date: 2006/09/26