Investigation in cardiac diseases

CVS

Methods

ECG(electrocardiograph) Chest X-rays Echocardiograph Ambulatory ECG Thallium 201 scanning (radionuclide scanning) Technetium-99-labeled sestamibi (radionuclide scanning) Cardiac catheterization Coronary angiography

ECG

Ecg is useful to detect the following abnormalities Cardiac arrhythmia Conduction defects Myocardial infarction or ischemia Myocardia hypotrophy Electrolyte imbalance Toxicity of certain drugs

X-rays

Heart size can be measured only from PA view of chest x-rays because in AP view cardiac shadow is large.

The maximum transverse diameter of the heart is compared with the maximum transvers diameter of the chest is measured from inside of the ribs, this is called cardiothoracic ratio (CTR)

It should be less than 50 %. Cardiomegaly and pericardial effusion cause an increase in

cardiothoracic ratio.

X-rays

Pericardial effusion produce globular shadow

X-rays

Left atrial dilatation manifests as prominence of left atrial appendage on the left heart border and a double atrial shadow to the right of the sternum (double right border)

X-rays

Left ventricular enlargement manifests as increased CTR and increased convexity of the left heart border.

X-rays

Right atrial enlargement manifests as projection of right border of heart into the right lower lung field

X-rays

Right ventricular enlargement manifests as CTR and an upward displacement of the apex of the heart.

X-rays

Enlargement of pulmonary artery manifests as a prominent bulge on the left heart border below the aortic knuckle.

X-rays

Lung field may indicate pulmonary hypertension by enlargement of the hilar vessels

Enlarged right lower lob artery Kerly’s B lines and pleural effusion may be present in cardiac failure

Echocardiograph

It is sensitive method to determination of Size of all four chambers of heart

Echocardiograph

Left ventricular function (ejection fraction)

Echocardiography

Regional wall motion abnormalities due to myocardial infarction Complication of myocardial infarction such as papillary muscles

dysfunction mitral regurgitation Structural valve abnormalities stenosis and regurgitation Cardiac output Ventricular hypertrophy Pericardial effusion Atrial and ventricular septic defects and other congenital defects.

Types of echocardiography

Two-dimensional real time echocardiography M-mod echocardiograph Doppler echocardiograph

Two-dimensional real time echocardiograph Detecting wall motion abnormalities Intracardiac masses Thrombi and tumors Endocarditic vegetations Congenital heart disease

M-mod echocardiography

Measurement of size of chambers of heart Calculation of ejection fraction and accurate timing of cardiac events

Doppler echocardiograph

Abnormal direction of blood flow Aortic mitral or mitral regurgitation Pulse-wave Doppler (PW) Continuous-wave Doppler (CW) Color doppler