DK2985_C000 1..28 - AlSharqia Echo Club

308 Transesophageal EchocardiographyD. Assessment of Right Ventricular FunctionAssessment of the right ventricular function is reviewed inChapter 9. Right ventricular dysfunction may present thefollowing features on TEE examination: right atrial andventricular dilatation (Fig. 13.16), decreased tricuspidannular longitudinal motion (Fig. 13.15), regional wallmotion abnormalities, shift of the atrial and the ventricularseptum towards the left, TR (Fig. 13.16), and plethora ofthe IVC. In addition, on hepatic venous flow PWDoppler interrogation, increased atrial reversal velocitycan be present in mild right ventricular dysfunctionwhile systolic reversal will be observed in more severecases (see Fig. 9.32).Acute right ventricular failure may result from pulmonaryembolism, right ventricular infarction, poor preservationof the RV by cardioplegia during CPB, airembolism to the right coronary artery, significant pulmonaryhypertension or right ventricular dysfunctionsecondary to left ventricular dysfunction.The diagnosis of right ventricular dysfunction before(70) or after (71) CPB has prognostic and therapeuticimplications. Although not systematically assessed incardiac surgical patients, right ventricular dysfunction isassociated with higher mortality in patients with hypotensiondespite inotropic therapy: the hospital mortality wasas high as 86% compared with 30–40% for patients withmoderately impaired or normal right ventricular functionwith severe left ventricular systolic dysfunction and only15% for those with normal RV and left ventricular systolicfunction (71). More recently, Maslow et al. (70) found thatthe presence of pre-CPB right ventricular dysfunctiondefined as a RV FAC ,35% predicted a poor outcomeafter CABG in patients with severe left ventricular systolicdysfunction. Patients with poor RV FAC required a longerduration of mechanical ventilatory support (12 vs 1 day,p , 0.01), a longer stay in the Intensive Care Unit (ICU)(14 vs 2 days, p , 0.01) and in the hospital (14 vs7 days, p ¼ 0.02); left ventricular diastolic dysfunctionwas more frequent and severe in these patients while improvementin left ventricular ejection fraction immediatelyafter CPB was decreased (4.1 + 8.3% vs 12.5 + 9.2%,p ¼ 0.03). Finally, all patients with poor right ventricularfunction died within two years of surgery, while 94% ofpatients with preserved right ventricular function survivedbeyond that period.E. Assessment of Diastolic FunctionFor a complete discussion of diastolic function, the readeris referred to Chapter 9. Bernard et al. (72) recently foundthat diastolic dysfunction is encountered in 30% ofpatients undergoing cardiac surgery and that its presencebefore CPB predicts difficult weaning and the need forinotropic support at the end of the procedure and up to12 h postoperatively.The clear effect of CPB, transient global ischemia,CABG, and cardioplegic solutions on the left ventriculardiastolic function is controversial. Indeed, while myocardialrevascularization improves left ventricular diastolicstiffness and Doppler indices of ventricular relaxationwhen evaluated weeks to months after surgery (73), onlya few studies have documented the effects of CABG onleft ventricular diastolic function in the early postoperativeperiod. The potential improvement in diastolic function byrevascularization could be offset by global ischemiaduring the cardioplegic arrest. If changes in the mitralinflow Doppler profile suggesting diastolic dysfunctionare described post-CPB, no clear change in ventricularrelaxation could be demonstrated after statistical correctionfor the effect of HR on the mitral indices (74). In fact,Humphrey et al. (75) have reported an improvement indiastolic relaxation after CABG and CPB using left ventricularintracavitary pressure and dimension measurements.F. Air DetectionDuring valvular heart surgery, and occasionally duringCABG, when veins are anastomosed to the ascendingAo, air is introduced into the heart cavities and may leadto coronary and cerebral embolism. Transesophagealechocardiography is useful to detect the presence of intracardiacair and to assess the efficacy of the measures toeliminate it. Two types of intracardiac air are encountered:1. Air bubbles: these present as highly mobile,strongly echogenic dots, often accompanied byside lobe and reverberation artifacts with acousticshadowing. Because of their buoyancy, bubbleswill gather in the superior aspects of cardiacchambers (see Fig. 9.42). Dynamic tearing awayof small air bubbles from the surface of an airpocket into the cardiac chambers can also beobserved and is known as the popcorn sign.2. Pooled air: this is depicted as a highly mobile,strongly echogenic line or area adjacent to thewall at the highest level in each chamber and alsoaccompanied by side lobe and reverberationartifacts with acoustic shadowing.Orihashi et al. (76) prospectively looked for the presenceof intracardiac air with TEE in 13 consecutivepatients undergoing left cardiotomy. The most frequentlocation of air retention was the right upper pulmonaryvein (RUPV) (13/13), followed by the LV (9/13), theLA (8/13), and the right sinus of Valsalva (8/13). Allpatients undergoing right cardiotomy displayed air trappingin the main and the right pulmonary arteries. Air in