Hội nghị Nhịp học Toàn quốc - Hà nội - 11/2016 Vietnam National Rhythm Conference Lựa chọn nghiệm pháp gắng sức cho bệnh nhân bloc nhánh trái bệnh nhân tạo nhịp tim? Selection of stress test for patients with paced ventricular rhythm or left bundle branch block TS NGUYỄN THỊ THU HOÀI VIỆN TIM MẠCH QUỐC GIA VIỆT NAM Indications for Stress Testing • AHA/ACC endorse many indications for stress testing • 11 Class I indications • Class IIa indications • 14 Class IIb indications Gibbons et al Circulation 2002;106:1883 Categories of Patients • Symptomatic patients without known CAD • Patients with known CAD ± symptoms • Patients with recent myocardial infarction Categories of Patients • Asymptomatic patients – – – – Type diabetes Multiple risk factors Starting exercise program Hypertension • Valvular heart disease • Heart failure • Heart rhythm disturbances Choice of Stress Testing Modality in Different Clinical Settings Localize ischemia or assess viability? No Marked baseline ECG abnormalities, digitalis, previous revascularization? No Able to exercise? No Yes Standard Stress ECG Yes Able to exercise? No Yes Yes Able to exercise? No Yes Pharmacologic imaging study Exercise imaging study Information from Stress Test • Diagnostic testing – Establish presence of coronary artery disease – ST segment changes (ischemia) • Prognostic testing – Estimate long-term survival – Estimate short-term or long-term risk of CV event • FAC or peak VO2 • Duke Treadmill Score • Heart rate responses Stress testing in LBBB  LBBB prevalence increases with age (17% at age 80 in Northern Europe)  Prevalence of CAD in patients with LBBB: 30% 50%  Confers an adverse prognosis Stress testing in LBBB Stress testing in LBBB ACC/AHA 2002 guidelines on exercise testing: There is NO level of ST segment depression that confers diagnostic significance during exercise ECG testing in patients with LBBB Paced Ventricular Rhythm  A paced right ventricular rhythm produces LBBB on the ECG  Like LBBB, a paced ventricular rhythm produces false positive defects on exercise rMPI if pacing continues during exercise Paced Ventricular Rhythm  The effect of pacing on septal radionuclide uptake: thallium rMPI and regional myocardial blood flow measurements were obtained during RV pacing and during RA pacing  Thallium uptake and blood flow were homogeneous throughout the LV during RA pacing  Septal abnormalities during RV pacing, as septal thallium uptake was reduced by 31% with a comparable reduction in blood flow Hirzel HO, Am J Cardiol 1984 Paced Ventricular Rhythm  Inferoposterior, inferior, and apical walls are the most common sites of false positive perfusion defects with right ventricular pacing in contrast to the septum in patients with LBBB  Impaired microvascular flow may contribute to these defects Hirzel HO, Am J Cardiol 1984 Paced Ventricular Rhythm JACC, 1997 Paced Ventricular Rhythm  The LV seems to be activated much more rapidly, while QRS duration and electromechanical delay are much longer with RV pacing  The extent of incoordinate wall motion may be much greater with LBBB Paced Ventricular Rhythm Diagnosis: As with LBBB, adenosine or dipyridamole rMPI is recommended by the ACC/AHA guidelines for the diagnosis of suspected CAD in patients with a paced ventricular rhythm Dobutamine stress echocardiography vs exercise rMPI in patients with paced rhythm Specificity was much higher with dobutamine echocardiography (92% vs 31%), which also had a sensitivity of 88% Ciaroni S, Echocardiography 2000 RECOMMENDATIONS The 2007 ACC/AHA guidelines: Evaluation by either vasodilator rMPI or dobutamine stress echocardiography is recommended in patients with LBBB, noting that the diagnostic accuracy of exercise imaging (rMPI or echocardiography) is inferior (due to low specificity) in this population based upon studies RECOMMENDATIONS Exercise imaging (rMPI or echocardiography) or dobutamine rMPI or the combination of exercise and dipyridamol stress is not recommended in patients with LBBB RECOMMENDATIONS The 2003 ACC/AHA/American Society of Nuclear Cardiology Task Force on cardiac radionuclide imaging also concluded that vasodilator rMPI is preferred over exercise rMPI in patients with LBBB RECOMMENDATIONS The 2002 ACC/AHA chronic angina guidelines recommend use of vasodilator rMPI in patients with a ventricular paced rhythm; this recommendation was not changed by the 2007 update SUMMARY  Vasodilator rMPI and dobutamine stress echocardiography are more specific than exercise rMPI and exercise echocardiography for the diagnosis of coronary artery disease in patients with LBBB  2007 ACC/AHA guidelines recommended the use of vasodilator rMPI or dobutamine stress echocardiography for the diagnosis of coronary artery disease in this patient population SUMMARY In patients with a ventricular paced rhythm:  ACC/AHA recommended: stress echocardiography may be more specific, vasodilator rMPI may be indicated in this patient population as well  For those patients with LBBB or ventricular paced rhythm in whom exercise is possible and important, exercise rMPI may be performed Further testing is not necessary if no perfusion abnormalities are identified THANK YOU VERY MUCH! ... (rMPI) False possitive rate in LBBB: 10-20% 383 bn bloc nhánh trái: 206 gắng sức thể lực 127 adenosin 50 dobutamine Do đồng khử cực muộn phần trái VLT: VLT co bóp vào cuối TK tâm thu, thất giãn,... stress echo significantly improved risk stratification in those without previous MI, but not in those with prior MI Cortigiani, Am J Med 2001 Exercise echocardiography LBBB Siêu âm gắng sức xe... stress echocardiography vs exercise rMPI in patients with paced rhythm Specificity was much higher with dobutamine echocardiography (92% vs 31%), which also had a sensitivity of 88% Ciaroni S, Echocardiography