CHF and Left Ventricular Dysfunction

An estimated one-third of preoperative cardiac deaths result from CHF. De-compensated CHF, manifested by an elevated jugular venous pressure, an audible third heart sound, or evidence of pulmonary edema on physical examination or chest radiography, significantly increases the risk of preoperative pulmonary edema (Rought 15%) and cardiac death (2-10%). Elective surgery should be postponed in patients with decompensated CHF until it can be brought under control.



   Patients with compensated left ventricular dysfunction are at increased risk for preoperative pulmonary edema.One large study found that patients with a left ventricular ejection fraction of < 50% had an absolute risk of 12% for postoperative CHF compared with 3% for patients with an ejection fraction > 50%. Such patients should continue taking all medications for chronic heart failure up to the day of surgery. Patients receiving digoxin and diuretics should have serum electrolyte and digoxin levels measured prior to surgery because abnormalities in these levels may increase the risk of preoperative arrhythmia. Clinicians must be caution not to give too much diuretic, since the volume-depleted patient will be much more susceptible to intraoperative hypo-tension. Preoperative echocardiography or radionuclide angiography to assess left ventricular function should be considered when there is suspicion of left ventricular dysfunction and when the cause of left ventricular dysfunction is in question. The surgeon and anesthesiologist should be made aware of the presence and severity of left ventricular dysfunction so that appropriate decisions can be made regarding perioperative fluid management and intraoperative monitoring.