Lựa chọn nghiệm pháp gắng sức nào cho bệnh nhân bloc nhánh trái hoặc bệnh nhân được tạo nhịp tim? - Nguyễn Thị Thu Hoài

Lựa chọn nghiệm pháp gắng sức nào 
cho bệnh nhân bloc nhánh trái hoặc 
bệnh nhân được 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 
Hội nghị Nhịp học Toàn quốc - Hà nội - 11/2016 
 Vietnam National Rhythm Conference 
Indications for Stress Testing 
• AHA/ACC endorse many indications for 
stress testing 
• 11 Class I indications 
• 8 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 2 diabetes 
– Multiple risk factors 
– Starting exercise program 
– Hypertension 
• Valvular heart disease 
• Heart failure 
• Heart rhythm disturbances 
Able to exercise? 
Choice of Stress Testing Modality in Different Clinical Settings 
Localize ischemia or assess viability? 
Able to exercise? 
Yes No 
Marked baseline 
ECG abnormalities, digitalis, 
previous revascularization? 
Standard Stress ECG 
Pharmacologic 
imaging study 
Exercise 
imaging study 
Yes 
No 
No Yes 
No Yes 
Able to exercise? 
Yes 
No 
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 
Exercise and pharmacologic stress radionuclide 
myocardial perfusion imaging (rMPI) 
False possitive rate in LBBB: 10-20% 
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Periyanan Vaduganathan, JACC 1996 
383 bn bloc nhánh trái: 
206 gắng sức thể lực 
127 adenosin 
50 dobutamine 
Do mất đồng bộ và khử cực muộn 
ở phần trái của VLT: VLT co bóp 
vào cuối TK tâm thu, khi đó thất 
vẫn đang giãn, hạn chế tưới máu 
TK đầu tâm trương, đây là giai 
đoạn bắt xạ tưới máu. 
Downloaded From:  on 11/25/2016
O’Keefe JACC 1993 
For prognosis: Vasodilator rMPI also provides 
important prognostic information in patients with 
CHD, which is incremental to clinical assessment 
Exercise and pharmacologic stress radionuclide 
myocardial perfusion imaging (rMPI) 
Mairsse 1995, Marwick 2013, Haft 2015 
Dobutamine stress echocardiography vs 
dobutamine rMPI in LBBB 
Dobutamine stress echo had a better accuracy and 
specificity than dobutamine rMPI because of false 
positive septal and anteroseptal perfusion defects 
associated with LBBB with rMPI 
Mairsse 1995, Marwick 2013, Haft 2015 
Dobutamine stress echocardiography vs 
dobutamine rMPI in LBBB 
Dobutamine stress echo had a better accuracy and 
specificity than dobutamine rMPI because of false 
positive septal and anteroseptal perfusion defects 
associated with LBBB with rMPI 
Mairsse 1995, Marwick 2013, Haft 2015 
Usefulness and limitations of dobutamine-atropine 
stress echo for the diagnosis of CAD in patients with 
LBBB - a multicenter study 
Usefulness and limitations of dobutamine-atropine 
stress echo for the diagnosis of CAD in patients with 
LBBB - a multicenter study 
The potential diagnostic value of DSE: 
 Stress-induced new or worsening wall motion 
abnormalities had a sensitivity of 68% and a specificity of 
91%. 
 However, sensitivity for the anterior circulation was lower 
(44%) in patients with abnormal septal thickening at rest. 
Geleijnse, Eur Heart J 2000 
Usefulness and limitations of dobutamine-atropine 
stress echo for the diagnosis of CAD in patients with 
LBBB - a multicenter study 
 Echocardiography provide pertinent information on the 
distribution and extent of CAD, chamber size, global and 
regional function, and valvular function. 
 Image interpretation can be more difficult when resting 
regional wall motion abnormalities exist, and interobserver 
variability remains a limitation. 
 Image quality can be reduced in certain patients because of 
body habitus or pulmonary disease. 
Thomas Allison, Mayo Clinic 
Accuracy of dobutamine–atropine stress 
echocardiography for the detection of 
coronary artery disease in the anterior and 
posterior circulation 
Accuracy of dobutamine–atropine stress 
echocardiography for the detection of 
coronary artery disease in the anterior 
circulation in patients with normal and 
abnormal rest septal thickening 
For prognosis: 
- 387 patients who underwent either dobutamine or 
dipyridamole stress echo 
- Follow-up 29 months: patients with evidence of ischemia 
on stress echo had significant reductions in 5 year survival 
(77% vs 92%) and 5 year survival free of a MI (60% vs 
87%). 
- Pharmacologic 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 in LBBB Siêu âm gắng sức bằng xe đạp lực kế Siêu âm gắng sức bằng thảm chạy 
Exercise-induced wall motion abnormalities had an overall sensitivity of 
76% and a specificity of 83%. The sensitivity was 100% for LAD but only 
46% and 40% percent for LCx and RCA. 
Heller, 2011 
Mordi 2014: 82 patients with LBBB, suspected CAD 
Dobutamine stress CMR (DSCMR) had higher 
specificity (87.5% vs 72.9%), negative predictive value 
(80.8% vs 67.3%), accuracy (80.4% vs 72.0%) than 
DSE. 
Dobutamine stress CMR vs 
Echocardiography in patients with LBBB 
Mordi I, JACC 2014 
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 
Hirzel HO, Am J Cardiol 1984 
 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 
Paced Ventricular Rhythm 
JACC, 1997 
 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. 
Paced Ventricular Rhythm 
Specificity was much higher with dobutamine 
echocardiography (92% vs 31%), which also had a 
sensitivity of 88% 
Dobutamine stress echocardiography vs 
exercise rMPI in patients with paced 
rhythm 
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!