About Left Ventricular Hypertrophy
Patients who present with a thickened left ventricle are likely suffering from left ventricular hypertrophy (LVH). There are a few different causes of LVH. It is a strong indicator of potential coronary complications, and there is a strong correlation between certain types of LVH and morbidity and mortality.
In patients presenting LVH, the muscle that forms the wall of the left ventricle becomes thicker. This can cause the ventricle to become stiff and not function properly. It is important that the left ventricle function properly, as it is the chamber of the heart responsible for supplying the rest of the body with oxygenated blood.
Types of LVH
There are a few types of thickened left ventricle that can show up as LVH. Athletic hypertrophy occurs in highly trained athletes, such as marathon runners, as a natural result of their intense, sustained heart rate. However, LVH in athletes generally regresses when they return to normal activity levels. Another form of LVH is hypertensive LVH. This occurs in patients with high blood pressure, which forces the heart to constantly pump harder. Yet another form is LVH as a complication of hypertrophic cardiomyopathy (HCM). This is a congenital disorder that affects the functioning of the heart muscle. It can cause LVH, but can also affect other parts of the heart.
Simply put, the cause of LVH is any condition that makes the heart pump harder than it needs to. Hypertrophy in athletes occurs in order to allow the heart to adapt to the increased workload. However, high blood pressure, or hypertension, is the most common cause by far. Higher pressures within blood vessels put a strain on the ventricle, making it difficult to satisfy the body’s needs. Also, narrowing of the aortic valve, or stenosis, obstructs blood flow from the left ventricle. In patients with HCM, the ventricle can become thick and stiff, which adds extra strain on the heart.
Left ventricular hypertrophy tends to develop slowly. The early stages of the condition are generally asymptomatic. As it progresses, symptoms should begin to appear. These can include shortness of breath (SOB), chest pain, fluttering or rapid, pounding heartbeat (palpitations), dizziness, fainting or easily become fatigued during physical activity. If a patient has high blood pressure, he or she should be regularly screened for coronary symptoms, particularly LVH, due to its high association with other complications.
Physicians diagnose LVH with a few tests. The most common is the electrocardiogram (EKG or ECG). This non-invasive procedure records the electrical activity of the heart muscle. Variances in the QRS complex, the largest of the waves on an EKG, can display the possibility of LVH. Another test to determine LVH is an echocardiogram, in which sound waves are used to form an image of the heart. To collect more information on a specific patient’s case, doctors may also use magnetic resonance imaging (MRI).
Physicians must treat the underlying cause of a patient’s LVH. If it is hypertensive in nature, the patients must work to lower their blood pressure. This usually includes lifestyle changes, such as exercise, quitting smoking, low sodium and low fat diets and, often, the addition of medications. Medications work at several levels. Thiazide diuretics stimulate the kidneys to expel water and sodium; they are the first method of blood pressure modifying medications. Angiotensin-converting enzyme (ACE) inhibitors cause blood vessels to dilate by impacting the renin-angiotensin-aldosterone system (RAAS), an endocrine pathway that causes blood vessels to constrict. An alternative to ACE inhibitors is angiotensin II receptor blockers (ARBs); they are used if ACE inhibitors cause side effects in the patient. Doctors may also prescribe beta blockers and calcium channel blockers to aid in the control of blood pressure
If the LVH is caused by aortic valve stenosis, doctors may have to surgically repair or replace the narrowed valve.
Mayo Clinic: Left Ventricular Hypertrophy
Cleveland Clinic Journal of Medicine: Left Ventricular Hypertrophy: An Overlooked Cardiovascular Risk Factor
Journal of American Medical Association: Left Ventricular Hypertrophy
European Heart Journal: Athletic Left Ventricular Hypertrophy: Long-term Studies are Required
Cleveland Clinic: Hypertrophic Cardiomyopathy Information
The Alan E. Lindsay ECG Learning Center in Cyberspace: Lesson VIII-Ventricular Hypertrophy