Guideline for preoperative echocardiography in elective adult surgical patients

The incidence of heart murmurs increases with age (between 15-25% in patients > 65 years), but with only a minority of these representing significant valvular heart disease. Above 75 years of age, the incidence of aortic stenosis is reported as 3%. Therefore, preoperatively the challenge is identifying those with significant cardiac disease whose management will be altered by the results of an echocardiogram without ordering unnecessary investigations in a significant number of patients.

In a published review O’Halleran and Kannam concluded that the aim of preoperative echocardiography should be to identify:

1. Significant aortic stenosis
2. Significant mitral stenosis
3. Significant left ventricular impairment (LVSD) not previously identified

This is based on the philosophy of targeting investigations that will alter patient management in the perioperative period i.e. identification of cardiac disease with potential haemodynamic compromise or cardiac disease that may influence anaesthetic technique.

There are no NICE (National Institute of Clinical Excellence) guidelines and SIGN guideline advice is restricted to the use of echocardiography in preoperative assessment of fractured neck of femur patients.

Clinical identification of severity of valvular heart disease may also be inexact, although the following signs and symptoms may be reassuring:

1. Exercise tolerance > 4 METS (Ability to walk up flight of stairs)
2. Normal systolic-diastolic difference (pulse pressure)
3. Normal ECG without evidence of left ventricular hypertrophy

Where a previous echocardiogram has been performed, the results of this should be reviewed prior to requesting a further echocardiogram. In many cases further referral will not be necessary:

• LVSD
  • Repeat echocardiogram not indicated if known severe LVSD.

• Minor valvular lesion e.g. mild aortic/mitral stenosis
  • Repeat echocardiogram if not within last 2 years.
  • For regurgitant lesions, if patient is clinically well/good exercise tolerance routine repeat echocardiogram not indicated.

• Significant Valvular lesion - Moderate to severe stenotic lesions
  • Repeat echocardiogram if not within last year.

The nature of surgery should also be considered. Where patients are scheduled for minor or day case surgery, echocardiography is only usually indicated in patients with signs of significant valvular heart disease e.g. angina/syncope or LVH/strain pattern on ECG.

Where similar surgery has been performed uneventfully within the last 6 months and the patient has remained clinically stable, echocardiography is not indicated for repeat surgical procedures.

For major/inpatient surgery, in the presence of an undiagnosed heart murmur, the patient’s exercise tolerance and ECG should be considered. Where the patient has a normal Exercise tolerance and normal ECG (no LVH or ischaemic changes), the likelihood of significant valvular heart disease is low and echocardiography is not routinely indicated.