Can you safely rule out heart disease before non cardiac surgery without echocardiography ?
Yes , in most situations . Experience suggest If the clinical examination is normal , ECG and X ray do not show any abnormality , significant heart disease is ruled out 95/ 100 times.
Please note : ECG and X-ray can not R/O Coronary artery disease by any degree of specificity .Echo cardiogram also miserably fails to predict future CAD. But EST / TMT does this very efficiently!
So where does the echo comes in the routine protocol in the screening of heart disease* ?
“No where” to be precise. It is only a gimmick . But many physicians and anesthetists are obsessed with echo estimated LV EF % They invariably ask for pre operative echo for cardiac risk stratification.
* On the other hand EST has a strong case for inclusion as a routine screening test before surgery.
What about diastolic dysfunction ?
ECG and X ray will not miss a manifest myocardial disease . However concealed diastolic dysfunction can not be detected without echo. It is very common to detect early forms of diastolic relaxation abnormalities in echo . Significance of this is not clear especially if it is grade 1 . In this situation patient’s functional capacity comes to our rescue. In a non functional patient any degree of diastolic dysfunction may increase the pulmonary capillary wedge pressure. These patients must be monitored and fluid administration should be be judiciously used.
Echocardiography rarely comes* in the routine scheme of things in the pre -operative cardiac risk assessment.
First question to ask before non cardiac surgery is about the symptoms and functional capacity . ( Do you climb 3 floors ? Walk 6 km /hr . lift 20kg over a flight of stairs , objectively walk 9 mts on treadmill with std Bruce) If he is asymptomatic and his functional capacity is good , for all practical purposes he will be fit for surgery in cardiac point of view .
Next , we need to look the ECG and X ray chest . If one of them shows some evidence for chamber enlargement / q waves etc ,an echocardiography is ordered .
If you really suspect CAD one should go for EST or doubtamine stress ECHO.
* Cardiologist lack professional freedom in new age medicine :
In this funny medical world , a cardiologist can not do what he wants to do . I have encountered surgeons and anesthetics refusing to take a patient for surgery without knowing the ejection fraction ! Once when I gave a surgical fitness without taking an echo there was a furore from the corporate desk of a big hospital . How can you make decision without these modern gadgets they seemed to ask ! Future looks lovely for cardiology !