Hypertension

Definition:

Sustained high blood pressure is known as hypertension.

Blood pressure is the pressure of the blood on the walls of the vessels.

Normal BP is 120/80 mmhg

In Hypertension BP > 130/90

         i.          Grade 1 hypertension: Also called Mild hypertension

Systolic BP = 130-140 mmhg          Diastolic BP = 85-90 mmhg

       ii.           Grade 2 hypertension: Also called Moderate hypertension

Systolic BP = 140-160 mmhg          Diastolic BP = 90-95 mmhg

      iii.           Grade 3 hypertension: Also called Severe hypertension

Systolic BP = 160-180 mmhg          Diastolic BP = 95-100 mmhg

     iv.            Grade 4 hypertension: Also called Malignant hypertension

Systolic BP >180mmhg          Diastolic BP > 110mmhg

Etiology:

Primary /Essential/ Ideopathic Hypertension:

In about 95% cases no cause of hypertension can be identified and the form of hypertensionis called primary or essential hypertension.

Secondary hypertension:

In about 5% cases, cause of hypertension can be discovered and the form of hypertension is called secondary hypertension.

Causes of secondary hypertension:

Ø  Renal and renovascular diseases:

o   Chronic renal failure

o   Glumerulonephritis

Ø  Endocrine disease:

o   Pheochromocytoma

o   Cushing’s syndrome

o   Conn’s syndrome

Ø  Drugs:

Oral contraceptive containing estrogens, NSAIDs and sympathomimetic agents

Ø  Alcohol consumption (chronic)

Ø  Coarctation of aorta ( localized narrowing of aorta)

Ø  Pregnancy

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Myocardial infarction (MI)

Definition:

The complete necrosis of the myocardium due to complete cessation (occlusion) of blood supply is called myocardial infarction.

Etiology:

·         Atherosclerotic plaque (unstable)

·         Embolic occlusion of coronaries

·         Severe and prolonged vasospasm

·         Drugs (Cocain and Amphetamine)

Clinical features:

Symptoms:

Ø  Chest pain

o   Severe and prolonged means more than 30 min not relieved with nitrates

o   Left side of chest and then radiates to left arm to left arm or back or neck

Ø  Vomiting

Ø  Sweating

Ø  Symptoms of heart failure in case of massive MI

o   Dizziness

o   Drowsiness

o   Severe shortness of breath

o   Unconsciousness (in some cases)

Signs:

§  Fist sign

§  Sweating/ diaphoresis

§  Vomiting

§  BP will be either increased or decreased

§  Pulse:

o   Tachycardia: Due to anxiety, low cardiac output or arrhythmias

o   Bradycardia: If there is inferior wall infarction

§  Chest (pericardium) examination:

Usually normal examination of the heart or having the following

o   Ventricular septal defect (VSD)

o   Pain systolic murmur (PSM)

o   A soft first heart sound

o   Fourth heart sound

o   Third heart sound reflects left ventricular dysfunction

§  Lungs:

Crepts at the bases of lungs

Investigation of MI:

ECG:

Ø  ST segment elevation

Ø  May be tachycardia or bradycardia

o   V3-V4 show anterior wall MI due to LAD involvement

o   II, III, aVF show inferior wall MI due to RCA involvement

o   I, aVL show high lateral wall MI due to circumflex

Cardiac enzymes:

Troponin T and I are raised up to 2 weeks while CK-MB remains elevated up to 3 days. Creatine kinase (CK) has three isoenzymes.

§  CK-MB: present in heart

§  CK-MM: present in skeletal muscle

§  CK-BB: present in brain

Echocardiography:

ü  It asses the myocardial movements i.e. whether Hypokinetic or Akinetic (no movement)

ü  It also asses the valves, whole function of the heart and aorta.

Routine investigation:

·         CBC (Complete Blood Count)

·         RBS (Random Blood Sugar)

·         Urea, creatinine

·         Serum electrolytes (especially K)

·         Cardiac X-ray

Treatment:

All the patients with suspected myocardial infarction should be confined to strict bed rest and admitted in hospital preferably in CCU.

General:

v  The aim of general treatment is to relieve the symptoms.

v  To relieve the pain, so strong analgesics especially opoid group (Morphine, codein) and anti-emetics (Gravinate) are used.

v  Complete bed rest for 24 hrs.

v  To treat other co-morbidities (diseases like HTN, DM)

Specific:

Antiplatelets:

Aspirin 300mg and clopidogril 300 mg are given as first (loading) dose then 75mg OD.

Thrombolytics:

§  Streptokinase

§  If once it is used then the patient become allergic to it

Beta blockers:

Atenolol, Propranolol, Metaprolol (cardio selective)

Nitrates:

Angised, isoket (nitroglycerine) should be given to relieve chest discomfort.

ACE inhibitors (Angiotensin Converting Enzymes):

They prevent or at least reduce the left ventricular dilatation and cardiac failure following myocardial infarction. These are Ramipril and Captopril (Tab. Capoten 25mg).

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Acute coronary syndrome (ACS)

Acute coronary syndrome includes unstable Angina and Non ST segment Elevation MI.

Angina:

Definition:

The clinical state in which a person have chest pain mostly on the left side with radiation to left arm and relieved within 30 minutes is called Angina.

Or

The clinical syndrome characterized by chest pain occurring as a result of decreased O2/ blood supply lasting within 30 minutes is called Angina.

Etiopathogenesis of Angina:

There is narrowing of the coronary arteries either by coronary vasospasm or by atherosclerosis (deposition of fats).

Types of Angina:

1.      Classical or exertional Angina:

It occurs due to increased myocardial oxygen during exertion or emotion in a patient of narrow coronary arteries. In such angina the typical pain is felt during exertion.

2.      Decubitus Angina:

This is angina that occurs when the patient lies down. It is the pain in chest during lying position usually present in case of cardiac failure.

3.      Prinzmetal’s or variant Angina:

This is angina that occurs at rest due to coronary vasospasm. The sympathetic overdrive (hyperactivity) causes the coronary vasospasm which leads episodic reduction of myocardial blood supply.

4.      Nocturnal Angina:

This is the angina that awakes the patient from sleep. It is chest pain at night during sleep especially because of vivid dreams.

5.      Unstable Angina:

This refers to angina of recent onset (less than one month), in which there is severe pain in chest last more than 10 to 15 minutes but less than 30 minutes and there is associated nausea/vomiting.

6.      Cardiac syndrome X:

There is a typical anginal pain with normal coronary arteries but there is some abnormality in the coronary microcirculation.

Risk factors of Angina:

·         Age: old age above 50 years

·         Sex: male> female above 50 years

·         Race: initially it was considered that rich people have greater chances of angina but now excluded

·         Hypertension (HTN): damaging the vessels

·         Diabetes Mellitus (DM): fat deposition

·         Smoking: damage the endothelium of the vessels

·         Obesity: hyperlipidemia

·         Family history: any angina in the family history

Clinical features of Angina:

Symptoms:

        i.            Chest pain:

Pain may arise on the following sites.

·         Left shoulder

·         Central chest

·         Throat

·         Epigastrium (if lower part of heart is involved)

·         Middle or lower of sternum

      ii.            Radiation of pain:

Pain can radiate to any dermatome from C8 to T4 including the following sites.

·         Left arm

·         Whole of chest (right chest)

·         Back of intrascapular region

·         Throat

   iii.            Weakness

    iv.            Nausea/ vomiting

       v.            Dyspnea:

Shortness of breath or abnormal awareness of respiration

Signs:

         i.            Fist sign: clenching of chest by fist

      ii.            Sweating

   iii.            Pale face

Investigations of Angina:

A.     ECG (ElectroCardioGraphy):

During pain:

Ø  ECG shows T wave inversion.

Ø  Elevation of ST segment in Prinzmetal’s angina

B.     ETT (Exercise Tolerance Test):

ü  Recording of ECG during exercise (on jogging machine)

ü  ST segment depression and T wave inversion

C.      ECHO cardiography:

·         It reveals the regional wall motion weakness.  

·         It asses the function of heart, valves and great vessels

D.     Cardiac enzymes:

Troponin I, troponin T and CK-MB are the enzymes normally present in the myocardium called cardiac enzymes. In case of MI they are increased in the blood but normal in Angina.

E.      Coronary angiography:

In this procedure, the coronary vessels are directly visualized in order to know the location and severity of coronary artery stenosis.

Management of Angina:

Treatment of Acute attack:

·         Nitrates:

Sublingual Nitrates (Angised) are given to relief the pain.

The MOA of nitrates is coronary and peripheral vasodilatation leading to decrease afterload and preload.

·         Ca channel blockers:

Amlopdipine (Norvasc 5mg) is used which block Ca channels leading to vasodilatation mainly arterial thus decreasing workload on the heart.

·         Analgesics:

Opoid analgesics (Morphine) along with (because of ‘vomiting’ side effect of opoid analgesics) antiemetic are used for the relief of pain.

Prevention of further attacks:

·         Anti platelets:

Aspirin and clopidogril (Noclot 75mg) are platelet-inhibiting agents preventing coronary thrombosis that is responsible for unstable angina and MI. The MOA is prevention of platelets adhesion with athero-sclerotic plaque and so the further stenosis or narrowing is prevented.

·         Nitrates:

Oral nitrates like Cardnit tablets are given to the patient.

·         Beta blockers:

Atenolol, propranolol, bisoprolol or metaprolol is used to reduce the myocardial oxygen demand by reducing the heart rate, force of cardiac contraction and therefore decreasing the cardiac output.

·         Lipid lowering drugs:

Rosuvastatin (Rast) or Atorvastatin (Ator) is used to lower the lipid level in the blood and thus preventing the further narrowing of the vessel.

Revascularization:

Indication of revascularization in the form of either Angioplasty (PTCA) or Bypass (CABG) is in Refractory Angina when the patient with unacceptable symptoms despite of maximum tolerable medical therapy or patient with left main coronary artery stenosis >50% with or without symptoms.

A.      Percutaneous Transluminal Coronary Angioplasty (PTCA): by the cardiologist

PTCA is performed by passing a fine guide-wire with deflated balloon through femoral artery, moved up to the diseased coronary artery. The balloon is then positioned across the stenotic area and inflated under pressure causing the dilatation of lumen. Now metallic stent is inserted that significantly reduces the chances of restenosis.

B.      Coronary Artery Bypass Grafting (CABG): by the surgeon

It is a major surgical method in which narrowed segments of coronary artery are bypasses using either free grafts of saphenous vein or the patient’s internal mammary artery (long thoracic artery). Radial artery graft is also commonly used now. Graft is sutured between aorta and coronary arteries distal to the obstruction.

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