Cardiology: Echocardiogram

Echocardiogram Notes

This is basically an ultrasound of the heart. It gives a reasonably accurate picture of the valves and chambers of the heart, and also gives an idea of the velocity of blood flow in certain areas (thus helping you to determine if there is backflow/ reduced flow in valve defects).

Structures visualised

-          Valves

-          All 4 chambers

-          Wall thickness

-          Amount of muscle contraction

-          Pericardium

-          Intracardiac masses

-          Ascending aorta

Types of echo

Transthoracic

-          The patient lies of their left hand side with their arm behind their head. The transducer is placed at various intercostal spaces to the left of the sternum, and at the anterior axillary line.

-          This is the preferred test for valve defects

Transoesophageal (TOE –Trans-Oesophageal Echocardiogram)

-          Usually performed under sedation (midazolam), and with facilities for resuscitation

-          It provides high resolution due to the probes proximity to the heart.

-          Provides good views of the posterior part of the heart – i.e. the left atrium, and descending aorta.

-          This is the investigation of choice for infective endocarditis, prosthetic valve management, and searching for causes of thromboembolism.

-          This is an invasive procedure!

Stress echocardiogram

-          You would normally do this is conjunction with a normal transthoracic echo and compare images. You can either stress the heart with exercise, or you can give an infusion of dobutamine.

-          It is basically used to evaluate CHD.

-          The presence of reversible systolic regional wall motion abnormalities are characteristic of CHD

-          This is basically an alternative to ETT (exercise tolerance testing) – but is not used as often

Uses of echo

-          Find valve dysfunction

-          Asses prosthetic valve function

-          Assessment of left ventricular function – can be used to estimate left ventricular ejection fraction

-          Atrial fibrillation

-          Congenital heart disease

-          Cardiomyopathy

-          IE

-          After embolic stroke – to try and find a possible cause; e.g. patent foramen ovale.

-          Pericardial disease

Other stuff

These things are generally not looked for on ECHO, unless you especially specify them to look!:

-          Right ventricular function

-          Diastolic function

-          Possible cause of stroke

Notes by Tom Leach