ARRHYTHMIA AS SECONDARY DISEASEHARIKRISHNA SHEEJA512 #

CORONARY ARTERY DISEASE• CAD happens when the arteries that supply blood to heart

muscle become hardened and narrowed. • This is due to the buildup of cholesterol and other material,

called plaque, on their inner walls.• This buildup is called atherosclerosis. As it grows, less blood

can flow through the arteries. As a result, the heart muscle can't get the blood or oxygen it needs. This can lead to chest pain (angina) or a heart attack.

• Most heart attacks happen when a blood clot suddenly cuts off the hearts' blood supply, causing permanent heart damage.

• Over time, CAD can also weaken the heart muscle and contribute to heart failure and arrhythmias. Heart failure means the heart can't pump blood well to the rest of the body. Arrhythmias are changes in the normal beating rhythm of the heart.

Heart With Muscle Damage and a Blocked Artery

•What Are the Signs and Symptoms of Coronary Heart Disease?

• A common symptom of coronary heart disease (CHD) is angina. Angina is chest pain or discomfort that occurs if an area of your heart muscle doesn't get enough oxygen-rich blood.

• Angina may feel like pressure or squeezing in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back.

• Angina pain may even feel like indigestion. The pain tends to get worse with activity and go away with rest. Emotional stress also can trigger the pain.

• Another common symptom of CHD is shortness of breath. This symptom occurs if CHD causesheart failure.

• The severity of these symptoms varies. They may get more severe as the buildup of plaque continues to narrow the coronary arteries.

Signs and Symptoms of Heart Problems Related to Coronary Heart DiseaseSome people who have CHD have no signs or symptoms—a condition called silent CHD. The disease might not be diagnosed until a person has signs or symptoms of a heart attack, heart failure, or an arrhythmia (an irregular heartbeat).

How Is Coronary Heart Disease Diagnosed?EKG (Electrocardiogram)Stress TestingDuring stress testing, you exercise to make your heart work hard and beat fast while heart tests are done. If you can't exercise, you may be given medicine to raise your heart rate.Echocardiography.Chest X RayBlood TestsBlood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels might be a sign that you're at risk for CHD.Coronary Angiography and Cardiac Catheterization

How Is Coronary Heart Disease Treated?Treatments for coronary heart disease include heart-healthy lifestyle changes, medicines,medical procedures and surgery, and cardiac rehabilitation.

Heart-Healthy Lifestyle ChangesYour doctor may recommend heart-healthy lifestyle changes if you have coronary heart disease. Heart-healthy lifestyle changes include:Heart-healthy eatingMaintaining a healthy weightManaging stressPhysical activityQuitting smoking

Electrolytes are electrically charged minerals such as sodium, potassium, calcium, phosphate and magnesium. Your body uses electrolytes for several purposes. Its cells, especially nerve cells and muscle cells such as those in your heart, maintain an electrical potential that can signal the cell to perform an activity. Electrolytes flow into and out of the cells to produce an electrical current, such as the current that the heart relies on to contract. Imbalances in electrolytes can cause problems with the current and result in abnormal heart rhythms, known as arrhythmias.

ELECTROLYTIC IMBALANCE

Electrical and Chemical Signalling• The concentration of positively charged sodium

minerals in the blood outside of your heart cells is much higher than that inside.

• In contrast, potassium levels are much higher inside your cells than outside.

• At rest, your cells have an overall negative charge inside and positive charge outside.

• During times of activity, special protein channels open in your cells, letting sodium flow in and making them positive.

• This change causes nearby cells to open their protein channels as well

• The flow of sodium into heart muscle cells causes them to contract and pump blood.

• The sodium channels promptly close, and potassium channels open, allowing potassium to exit the cell and make it negative again. A pump restores the normal levels of sodium and pottasium.

Causes• When levels of sodium,

potassium and other minerals become abnormal, your heart can become more or less electrically charged, leading to abnormally timed contractions and an irregular heartbeat.

• Electrolyte imbalances are infrequently due to dietary restriction.

• Problems with hormone levels, such as those released from your adrenal or pituitary glands, can disrupt electrolyte levels.

• Kidney problems, genetic diseases and cancers are other possible causes.

Diagnosis• Your doctor can diagnose heart

arrhythmias from a history of symptoms such as palpitations, light-headedness, shortness of breath or chest pain, although these symptoms also occur in many other problems such as heart attacks or blood clots to the lungs.

• A physical examination can reveal an abnormal pulse and laboratory tests such as an electrocardiogram can measure the electrical activity of your heart.

• An echocardiogram uses sound waves to look at the beating of your heart.

• The diagnosis of electrolyte imbalances is similar in that a history and physical examination are crucial.

• Blood tests that measure your levels of electrolytes are also helpful.

Treatment• The treatment of abnormal heart

rhythms due to electrolyte imbalances depends on the severity of your abnormal heart rhythm and the nature of the electrolyte imbalance.

• Some situations may be urgent enough to require an external source of electricity to pace the heart.

• In other situations you may receive one or more medicines by mouth or intravenously.

• A doctor can temporarily adjust electrolyte imbalances by giving or restricting fluids and electrolytes, but you may require further intervention such as long-term medications—for example, if you have low hormone levels, you may receive hormone-replacement medication.

HEART MUSCLE DISEASE OR INFLAMMATION OF THE HEART• Both heart muscle disease (cardiomyopathy) and

inflammation of the heart muscle (myocarditis) affect the heart muscle.

• Cardiomyopathy changes the structure of your heart. The muscle may thicken and become stiffer, or the heart may dilate. Myocarditis is an acute inflammation of your heart muscle, usually caused by a viral infection. Acute inflammation may result in a dilated cardiomyopathy.

• These effects on your heart muscle weaken your heart so that it doesn't pump effectively, which can lead to heart failure.

What happens in hypertrophic cardiomyopathy (HCM)?

• In HCM the heart muscle becomes thickened (hypertrophies) in parts of the heart. In the normal heart, the muscle cells are regular and patterned. In HCM the cells of the heart muscle become irregular and disordered.

• The muscle surrounding the left ventricle is the area commonly affected. Sometimes the muscle around the right ventricle is also affected. The degree of thickening may vary in different places.

• How does the condition progress?

• The thickening of the heart muscle does not tend to progress once you stop growing. This means that, for many people, the symptoms remain stable during adulthood. Unfortunately, the symptoms gradually become worse for some people as the heart muscle becomes more stiff. Sometimes the function of the heart gradually deteriorates and heart failure may develop.

Postoperative Arrhythmias after Cardiac Surgery: Incidence, Risk Factors, and Therapeutic Management

Patient-Related Risk Factors(i) Age.(ii) Structural Heart Disease.

iii) Extracardiac Comorbidities

Surgery-Related Risk Factors(i) Trauma and Inflammation.(ii) Hemodynamic Stress.(iii) Ischemic Injury.(iv) Perioperative Drugs. Therapy

Recurrence and Prophylaxis

Irregular heart rhythms can also occur in normal, healthy hearts. Arrhythmias can also be caused by certain substances or medications, such as caffeine, nicotine, alcohol, cocaine, inhaled aerosols, diet pills, and cough and cold remedies. Emotional states such as shock, fright or stress can also cause irregular heart rhythms