1. Investigations of the Cardiovascular system

2. Investigations of the Cardiovascular system
Electrocardiography
Radiology
Echocardiography
CT imaging
MRI
Cardiac catheterization
Radionuclide imaging

3. Electrocardiography (ECG)
uses:
To determine heart rhythm
Status of the conducting system
To diagnose myocardial ischemia or infarction
Chamber enlargement and hypertrophy
Effects of drugs & metabolic disorders (electrolyte imbalance, acidosis, etc.)

4. The ECG Leads Standard leads (Bipolar Leads) Augmented leads
Chest leads

5. Standard leads (Bipolar Leads)
Lead I: between left arm & right arm
Lead II: between right arm & left leg
Lead III: left arm and left leg

6. Augmented Limb Leads aVR: right arm and central terminal
aVL: left arm and central terminal
aVF: left foot and neutral central terminal

7. Chest Leads Six leads: V1-V6 V1 & V2: face the RV
V3 & V4: face the septum
V5 & V6: face the LV.

8. Exercise ECG In patients with angina, the resting ECG may be normal
The principle of the test is to stress the heart and observe for ECG changes of ischemia
ECG and BP are continuously recorded while the patient is exercising on a bicycle or a treadmill

9. INDICATIONS FOR EXERCISE TESTING: To confirm the diagnosis of angina
To evaluate stable angina
To assess prognosis following myocardial infarction
To assess outcome after coronary revascularisation, e.g. coronary angioplasty
To diagnose and evaluate the treatment of exercise-induced arrhythmias

10. Exercise ECG Positive exercise test: High risk ETT:
> 2mm ST segment depression
> 1mm ST segment elevation
High risk ETT:
Low threshold for ischemia
Fall in BP during exercise
Widespread, marked or prolonged ischemic changes
Exercise-induced arrhythmia
contraindicated in the presence of unstable angina, decompensated heart failure and severe hypertension and aortic stenosis.

11. Ambulatory ECG Monitoring (Holter)
Continuous recording of ECG over 24 hours or more
Used to detect transient episodes of ischemia or arrhythmia which can rarely be captured during routine, ordinary ECG recording

12. Radiology of the Heart Chest X-ray: Postero-anterior view (PA view):
Size of the heart
Shape of the heart
Specific chamber enlargement
Status of the pulmonary circulation

13. Radiology of the Heart Cardiac size: Cardio-thoracic ratio (CTR):
Normally < 0.5
Enlargement of the heart (cardiomegaly):
LV dilatation and dysfunction
Pericardial effusion

14. Radiology of the Heart Left atrial enlargement:
Straight heart border (LA appendage)
Widening of the carinal angle
Double contour of the right heart border

15. Radiology of the Heart LV enlargement: Enlarged cardiac silhouette
Prominent left heart border

16. Radiology of the Heart RV enlargement: Cardiomegaly
Straightening of the left heart border
Apex displaced upwards
Right atrial enlargement:
Prominence of the right border of the heart

17. Radiology of the Heart Lung fields:
Congestion & edema in patients with left heart failure
Increased blood flow (prominent arteries and veins) in shunt lesions
Oligemic lungs in pulmonary stenosis
Pleural effusions in advanced heart failure

18. Two Dimensional Echocardiography
Ultrasound beam passing through the heart generates cross sectional images or “slices” of the heart
Various structures can be seen in real time

19. Doppler Echocardiography
The derived signal can be plotted graphically against time
Or, color can be assigned for the reflected signal and superimposed over the 2D image (color flow mapping)

20. Two Dimensional Echocardiography indications
Assessment of LV function
Diagnosis & quantitation of severity of valvular lesions
Identification of vegetations
Identifying the source of systemic embolism
Detection of pericardial effusion

21. Transoesophageal echocardiography
an ultrasound probe in the shape of an endoscope is passed into the oesophagus and positioned immediately behind the left atrium.
The high-quality “very clear” images obtained are valuable for investigating patients with:
prosthetic (especially mitral) valve dysfunction
congenital abnormalities (e.g. atrial septal defect),
aortic dissection
infective endocarditis to see vegetations that are too small to be detected by ordinary echocardiography
systemic embolism.

22. COMPUTED TOMOGRAPHIC (CT) IMAGING
Useful for imaging the chambers of the heart, the great vessels, the pericardium and surrounding structures.
In practice it is most useful for imaging the aorta in suspected aortic dissection.
Helical CT with multi-slice technology provides images are almost completely devoid of motion artefact

23. Non-invasive imaging of the coronary arteries (CT coronary angiography)
is becoming comparable to conventional coronary arteriography.
It is possible to identify coronary artery calcification that gives a correlation with the degree of atherosclerotic disease and quantification of calcified plaques has been used for risk stratification.

24. non-invasive imaging: CT and MRI
Chambers of the heart
The great vessels
The pericardium
Diseases of the aorta
The pulmonary arteries
Non-invasive imaging of the
coronary arteries

25. Invasive investigation: cardiac catherization
A small tube is passed into the heart via a peripheral artery or vein under fluoroscopic guidance
Pressure can be measured, flow volumes calculated, radiographic dyes can be injected to outlime the specific chamber or vessel (angiography)

26. Left heart catheterisation is mainly used to assess coronary artery disease but is also used to evaluate disease of the mitral valve, aortic valve and aorta.
Left ventriculography is used to determine the size and function of the left ventricle
coronary angiography is used to detect stenoses and guide revascularisation procedures such as balloon angioplasty and stenting.

27. RADIONUCLIDE IMAGING Blood pool imaging to assess ventricular function
Myocardial perfusion imaging

28. Thank You