Common Diseases Of Cardiovascular System

There are so many diseases that contributed to heart diseases,but we will discuss only coronary heart diseases. At the end of this article, you will distinguish between:

 Angina pectoris vs Myocardial infarction

ANGINA PECTORIS

= is chest pain due to ischemia of the heart muscle, generally due to obstruction or spasm of the coronary arteries.

Classification

1. Stable angina.

2. Unstable angina.

3. Microvascular angina.

 Etiology:

Develops mainly in people over 40 years old,and predominantly in men and mental workers.

1. Atherosclerosis.

2. Bad habit (smoking and alcohol).

3. Bad diet (high cholesterol and sugar).

4. Obesity.

5. Hypertension and stress.

How to read ECG?

What is ECG?

-ECG is used to measure activity of heart,detected by electrodes attached to the surface of the skin and recorded by a device external to the body. The recording produced by this noninvasive procedure is termed an electrocardiogram ( ECG or EKG).

Functions of ECG

1.  It can give information regarding the rhythm of the heart
2. It can also give information regarding the balance of salts (electrolytes) in the blood
3. Reveal problems with sodium channels within the heart muscle cells
4. Can identify if the heart muscle has been damaged in specific areas, though not all areas of the heart are covered.

Waveforms of ECG

• P wave: depolarization of the right and left atria

•  QRS complex: right and left ventricular depolarization

•  ST-T wave: ventricular repolarization

• U wave:  probably represents "afterdepolarizations" in the ventricles

•   PR interval: time interval from onset of atrial depolarization (P wave) to onset of ventricular depolarization (QRS complex)
• QRS duration: duration of ventricular muscle depolarization due to contraction of this large muscle mass

•  QT interval: duration of ventricular depolarization and repolarization

• RR interval: duration of ventricular cardiac cycle (an indicator of ventricular rate)