Ischemic Heart Disease (IHD)

Ischemic heart disease (IHD), is the most common type of heart disease and cause of heart attacks.The disease is caused by plaque building up along the inner walls of the arteries of the heart, which narrows the arteries and reduces blood flow to the heart.
While the symptoms and signs of coronary artery disease are noted in the advanced state of disease, most individuals with coronary artery disease show no evidence of disease for decades as the disease progresses before the first onset of symptoms, often a “sudden” heart attack, finally arises. Symptoms of stable ischaemic heart disease include angina (characteristic chest pain on exertion) and decreased exercise tolerance. Unstable IHD presents itself as chest pain or other symptoms at rest, or rapidly worsening angina. The risk of artery narrowing increases with age, smoking, high blood cholesterol, diabetes, high blood pressure, and is more common in men and those who have close relatives with CAD.

Principles in Ischemic Heart Disease

Major determinant of O₂ demand is intramyocardial tension

Which is Pressure  X  Radius / Wall thickness (Laplace law)

As most flow in coronary is diastolic, perfusion pressure, intramyocardial pressure and vessel patency play equally important role.

Subendocardium is more vulnerable to ischaemia

Pathogenesis of Atherosclerosis

Elevated LDL leads to platelet adherence and increased permeability.

Platelet growth factor causes smooth muscle proliferation and increased pinocytosis of lipids.

Increase vascular permeability causes more penetration of LDL.

End result is formation of atheromatous plaques.

Signs and Symptoms of Ischemic Heart Disease

Angina (chest pain) that occurs regularly with activity, after heavy meals, or at other predictable times is termed stable angina and is associated with high grade narrowings of the heart arteries. The symptoms of angina are often treated with betablocker therapy such as metoprolol or atenolol. Nitrate preparations such as nitroglycerin, which come in short-acting and long-acting forms are also effective in relieving symptoms but are not known to reduce the chances of future heart attacks. Many other more effective treatments, especially of the underlying atheromatous disease, have been developed.

Coronary Risk Factors

a) Male Sex

b) Positive family history  of Coronary Artery Disease (CAD)

c)  Hypertension

d) Diabetes mellitus

e) Hyperlipidemia, especially LDL;  HDL has a protective role,

f) Smoking (particularly in young)

g) Obesity

h) Oral contraceptives

i) Sedentary occupation

j) Type A personality (ambitious aggressive, time and work oriented)

k) Homocystinemia

l)  Lipopotein  (i) chylomicron remnant

m) Chlamydia H.pylori, CMV infection

n) Antiphospholipid, Protein C and S deficiency.

o) Fixed obstruction exceeding 80% of lumen usually produces symptoms.

Risk factors in further

      Anxiety (Type A personality)

      Body build (and male sex)

      Cigarette smoking

      Diabetes

      Exercise lack

      Family history

      Gout

         Hypertension

         Hyperlipidemia

         Hyperhomocysteinemia

         Husband ! (incidence less in spinsters than married women)

Clinical types of Ischemic Heart Disease

1.       Angina pectoris  :  Stable

Unstable

Variant

2.       Cardiac infraction

3.       Ischemic cardiomyopathy

Diagnosis of Ischemic Heart Disease

For symptomatic patients, stress echocardiography can be used to make a diagnosis for obstructive coronary artery disease.The use of echocardiography is not recommended on individuals who are exhibiting no symptoms and are otherwise at low risk for developing coronary disease.

CAD has always been a tough disease to diagnose without the use of invasive or stressful activities. The development of the Multifunction Cardiogram (MCG) has changed the way CAD is diagnosed. The MCG consists of a 2 lead resting ECG signal is transformed into a mathematical model and compared against tens of thousands of clinical trials to diagnose a patient with an objective severity score, as well as secondary and tertiary results about the patients condition.

Diagnosis of Stable Angina

In “stable” angina, chest pain with typical features occurring at predictable levels of exertion, various forms of cardiac stress tests may be used to induce both symptoms and detect changes by way of electrocardiography (using an ECG), echocardiography (using ultrasound of the heart) or scintigraphy (using uptake of radionuclide by the heart muscle). If part of the heart seems to receive an insufficient blood supply, coronary angiography may be used to identify stenosis of the coronary arteries and suitability for angioplasty or bypass surgery.

Diagnosis of Acute caronary syndrome (ACS)

Diagnosis of acute coronary syndrome generally takes place in the emergency department, where ECGs may be performed sequentially to identify “EVOLVING CHANGES” (indicating ongoing damage to the heart muscle). Diagnosis is clear-cut if ECGs show elevation of the “ST segment”, which in the context of severe typical chest pain is strongly indicative of an acute myocardial infarction (MI); this is termed a STEMI (ST-elevation MI), and is treated as an emergency with either urgent coronary angiography and PTCA-Percutaneous Transluminal Coronary Angiogram (an interventional angioplasty with or without stent insertion) or with thrombolysis (“CLOT BUSTER” medication), whichever is available. In the absence of ST-segment elevation, heart damage is detected by cardiac markers (blood tests that identify heart muscle damage). If there is evidence of damage (infarction), the chest pain is attributed to a “non-ST elevation MI” (NSTEMI). If there is no evidence of damage, the term “unstable angina” is used. This process usually necessitates admission to hospital, and close observation on a coronary care unit for possible complications (such as cardiac arrhythmias – irregularities in the heart rate).

Treatment of Ischemic Heart Disease

Therapeutic options for Ischemic Heart Disease (IHD) today are based on three principles:
1. Medical treatment – drugs (e.g. cholesterol lowering medications, beta-blockers, nitroglycerin, calcium antagonists, etc.);
2. Coronary interventions as angioplasty and coronary stent-implantation.
3. Coronary artery bypass grafting (CABG – coronary artery bypass surgery).
Recent research efforts focus on new angiogenic treatment modalities (angiogenesis) and various (adult) stem cell therapies

In further

Statins, which reduce cholesterol, reduce risk of coronary disease.
Nitroglycerin
ACE inhibitors, which treat hypertension and may lower the risk of recurrent myocardial infarction[citation needed]
Calcium channel blockers and/or beta-blockers
Aspirin.

Life style modification

Lifestyle modification have been shown to be effective in reducing (and in the case of diet, reversing) coronary disease.

1. A whole-food plant-based diet
2. Weight control
3. Smoking cessation
4. Avoiding the consumption of trans fats (in hydrogenated oils)
5. Exercise Aerobic exercise, like walking, jogging, or swimming, can help decrease blood pressure and the amount of blood cholesterol over time.
6. Decrease psychosocial stress.