Evaluation of a new treadmill exercise protocol to unmask type 1 Brugada electrocardiographic pattern: can we improve diagnostic yield?

AIMS: High precordial leads (HPL) on the resting electrocardiogram (ECG) are widely used to improve diagnostic detection of type 1 Brugada ECG pattern (Br1ECGp). A parasympathetic activation marks the initial recovery phase of treadmill stress testing (TET), and this can be useful for detecting the typical ECG pattern. Our study aimed to evaluate the role of a new HPL-treadmill exercise testing (TET) protocol in detecting Br1ECGp fluctuation compared to resting HPL-ECG. METHODS AND RESULTS: 74 out of 163 patients of a Brugada syndrome (BrS) Brazilian cohort (GenBra Registry) underwent exercise testing with HPL-TET protocol. Precordial leads were displayed in strategic positions in the right and left parasternal spaces. The step-by-step analysis included ECG classification (as presence or absence of Br1ECGp) in standard vs. HPL leads placement in the following sequences: resting phase, maximal exercise, and the passive recovery phase (including 'quick lay down'). For heart rate recovery (HRR) measurements and comparisons, a Student's t-test was applied. McNemar tests compared the detection of Br1ECGp. The significance level was defined as P < 0.05. Fifty-seven patients (57/74; 77%) were male, the mean age was 49.0 ± 14, 78.4% had spontaneous BrS, and the mean Shanghai score was 4.5. The HPL-TET protocol increased Br1ECGp detection by 32.4% against resting HPL-ECG (52.7% vs. 20.3%, P = 0.001) alone. CONCLUSION: Stress testing using HPL with the passive recovery phase in the supine position offers an opportunity to unmask the type 1 Br1ECGp, which could increase the diagnostic yield in this population.

Treadmill exercise testing improves diagnostic accuracy in children with concealed congenital long QT syndrome.

BACKGROUND: Resting electrocardiogram (ECG) identification of long QT syndrome (LQTS) has limitations. Uncertainty exists on how to classify patients with borderline prolonged QT intervals. We tested if exercise testing could help serve to guide which children with borderline prolonged QT intervals may be gene positive for LQTS. METHODS: Pediatric patients (n = 139) were divided into three groups: Controls (n = 76), gene positive LQTS with borderline QTc (n = 21), and gene negative patients with borderline QTc (n = 42). Borderline QTc was defined between 440-470 (male) and 440-480 (female) ms. ECGs were recorded supine, sitting, and standing. Patients then underwent treadmill stress testing with Bruce protocol followed by a 9-minute recovery phase. RESULTS: Supine resting QTc, age, and Schwartz score for the three groups were: (a) gene positive: 446 ± 23 ms, 12.4 ± 3.4 years old, 3.2 ± 1.8; (b) gene negative: 445 ± 20 ms, 12.1 ± 2 years old, 2.0 ± 1.2; and (c) control: 400 ± 24 ms, 15.0 ± 3 years old. The three groups could be differentiated by their QTc response at two time points: standing and recovery phase at 6 minutes. Standing QTc ≥460 ms differentiated borderline prolonged QTc patients (gene positive and gene negative) from controls. Late recovery QTc ≥480 ms distinguished gene positive from gene negative patients. CONCLUSION: Exercise stress testing can be useful to identify children who are gene positive borderline LQTS from a normal population and gene negative borderline QTc children, allowing for selective gene testing in a higher risk group of patients with borderline QTc intervals and intermediate Schwartz scores.

Added value of exercise test findings beyond traditional risk factors for cardiovascular risk stratification.

BACKGROUND: Functional aerobic capacity (FAC) determined by treadmill exercise testing (TMET) is associated with cardiovascular (CV) disease mortality independent of traditional CV risk factors and is a potentially underutilized tool. The purpose of this study was to determine added prognostic value of reduced FAC and other exercise test abnormalities beyond CV risk factors for predicting total and CV mortality. METHODS: The TMET database was queried for Minnesota patients (≥30 years) without baseline CV disease from September 21, 1993, through December 20, 2010. Risk factors and exercise abnormalities including low FAC (<80% predicted), abnormal heart rate recovery (<13 bpm), and abnormal electrocardiogram (ST depression ≥1 mm regardless of baseline) were extracted. Mortality data were obtained through February 2016. Patients were divided into 9 groups by abnormality number (0, 1, or ≥2) and risk factors (0, 1, or ≥2). Cox regression was used to determine mortality risk according to exercise abnormalities/CV risk factors, adjusted for age and sex. RESULTS: 19,551 patients met inclusion criteria; 1271 (6.5%) died over 12.4 ±â€¯5.0 years' follow-up (405 [32%] CV deaths). Exercise abnormalities significantly modified risk for every number of CV risk factors. Hazard ratios (95% CI) for total mortality (0 vs ≥2 abnormalities) were 2.4 (1.9-2.9; P < .001) for 0 CV risk factors; 2.7 (2.2-3.3; P < .001), 1 risk factor; and 6.1 (4.8-7.7; P < .001), ≥2 risk factors. Similar results were noted for CV disease mortality. CONCLUSIONS: Exercise test abnormalities strongly predict mortality beyond traditional CV risk factors. Our results indicate that TMET should be considered for CV risk assessment.

The clinical study on the effect of Tongyang-Kuanxiong guanule (TKG) for the stable angina pectoris patients with the type of Qi and phlegm stasis / 国际中医中药杂志

Objective To observe the effect of Tongyang-Kuanxiong guanule combined with conventional western medicine for the stable angina pectoris (SAP) with qi and phlegm and blood stasis syndrome. Methods Eighty-six SAP patients who met the inclusion criteria were randomly divided into two groups according to the digital table method, with 43 cases in each group. The control group was treated with routine Western medical therapy. The observation group was given Tongyang-Kuanxiong guanule on the basis of the control group. Both groups were treated for 28 days. The TCM syndromes and angina pectoris scores were evaluated before and after treatment. The treadmill exercise test was used to observe the duration of exercise, the metabolic equivalent, the maximum value of ST segment depression, the heart rate at maximum load, the duration of ST segment depression. And the adverse reactions were recorded. Results The total effective rate was 88.4％ (38/43) in the observation group and 67.4％ (29/43) in the control group. The difference between the two groups was statistically significant (χ2=5.549, P=0.018). After treatment, the duration of exercise (9.5 ± 1.2 min vs. 8.6 ± 1.2 min, t=3.371), metabolic equivalent (10.8 ± 2.5 METs vs. 9.2 ± 2.4 METs, t=3.084) in the observation group were significantly higher than those in the control group (P<0.01 or P<0.05). The largest degree of ST segment changes (1.2 ± 0.6 mV vs. 1.9 ± 0.6 mV, t=5.484), and the duration of ST segment descent (125.0 ± 94.5 s vs. 162.4 ± 96.9 s, t=1.795) in the observation group were significantly lower than those in the control group (P<0.01 or P<0.05). Thefrequency of angina attacks (9.7 ± 1.6 times per week vs. 17.3 ± 2.1 times per week, t=18.778), duration of attacks (3.2 ± 1.4 min vs. 6.4 ± 1.5 min, t=10.146) consumption of nitroglycerin (1.3 ± 0.8 mg vs. 2.5 ± 0.8 mg, t=7.624) and Symptom score (8.3 ± 2.8 vs. 12.5 ± 3.1, t=6.593) in the observation group were significantly lower than the control group (P<0.01). Conclusions The Tongyang-Kuanxiong guanule can significantly improve the exercise tolerance of SAP patients with qi and phlegm and blood stasis, reduce myocardial oxygen consumption, improve angina pectoris and reduce the number of angina attacks.

Impaired chronotropic response to physical activities in heart failure patients.

BACKGROUND: While exercise-based cardiac rehabilitation has a beneficial effect on heart failure hospitalization and mortality, it is limited by the presence of chronotropic incompetence (CI) in some patients. This study explored the feasibility of using wearable devices to assess impaired chronotropic response in heart failure patients. METHODS: Forty patients with heart failure (left ventricular ejection fraction, LVEF: 44.6 ± 5.8; age: 54.4 ± 11.7) received ECG Holter and accelerometer to monitor heart rate (HR) and physical activities during symptom-limited treadmill exercise testing, 6-min hall walk (6MHW), and 24-h daily living. CI was defined as maximal HR during peak exercise testing failing to reach 70% of age-predicted maximal HR (APMHR, 220 - age). The correlation between HR and physical activities in Holter-accelerometer recording was analyzed. RESULTS: Of 40 enrolled patients, 26 were able to perform treadmill exercise testing. Based on exercise test reports, 13 (50%) of 26 patients did not achieve at least 70% of APMHR (CI patients). CI patients achieved a lower % APMHR (62.0 ± 6.3%) than non-CI patients who achieved 72.0 ± 1.2% of APMHR (P < 0.0001). When Holter-accelerometer recording was used to assess chronotropic response, the percent APMHR achieved during 6MHW and physical activities was significantly lower in CI patients than in non-CI patients. CI patients had a significantly shorter 6MHW distance and less physical activity intensity than non-CI patients. CONCLUSION: The study found impaired chronotropic response in 50% of heart failure patients who took treadmill exercise testing. The wearable Holter-accelerometer recording could help to identify impaired chronotropic response to physical activities in heart failure patients. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT02358603 . Registered 16 May 2014.

Exercise-induced ventricular arrhythmias and vagal dysfunction in Chagas disease patients with no apparent cardiac involvement

INTRODUCTION : Exercise-induced ventricular arrhythmia (EIVA) and autonomic imbalance are considered as early markers of heart disease in Chagas disease (ChD) patients. The objective of the present study was to verify the differences in the occurrence of EIVA and autonomic maneuver indexes between healthy individuals and ChD patients with no apparent cardiac involvement. METHODS : A total of 75 ChD patients with no apparent cardiac involvement, aged 44.7 (8.5) years, and 38 healthy individuals, aged 44.0 (9.2) years, were evaluated using echocardiography, symptom-limited treadmill exercise testing and autonomic function tests. RESULTS : The occurrence of EIVA was higher in the chagasic group (48%) than in the control group (23.7%) during both the effort and the recovery phases. Frequent ventricular contractions occurred only in the patient group. Additionally, the respiratory sinus arrhythmia index was significantly lower in the chagasic individuals compared with the control group. CONCLUSIONS : ChD patients with no apparent cardiac involvement had a higher frequency of EIVA as well as more vagal dysfunction by respiratory sinus arrhythmia. These results suggest that even when asymptomatic, ChD patients possess important arrhythmogenic substrates and subclinical disease. .

Analysis of treadmill exercise test on patients with left main coronary artery or proximal anterior descending obstruction / 中国综合临床

Objective To explore the significance of treadmill exercise test (TET) in identifying left main coronary artery(LMD) obstruction from proximal left anterior descending(LAD) obstruction.Methods Patients with positive in the TET of the Central Hospital of Dalian from Jan.2008 to Dec.2013 were enrolled in this study and they were divided into LMD group with 21 cases and LAD group with 35 cases according to the results of coronary angiography.Retrospectively study was conducted to analyze the exercise time,the start time of ST segment change,the lead of ST segment between groups.Results Lead aVR ST segment elevation(≥0.10 mV) was 85.7％ (18/21) in the LMD group and 62.9％ (22/35) in the LAD group.Lead aVR ST segment elevation in the LM group was ((0.16 ± 0.07) mV,higher than in the LAD group ((0.11 ± 0.07) mV ; t =2.614,P ＜ 0.05).Accompany ST segment depression of leads and cumulative ST segment depression were (5.7 ±1.7) pcs and (1.13 ±0.42) mV in LMD group,significantly higher than those of LAD group((4.6 ± ± 1.8) pcs and (0.87 ± 0.32) mV ; t =2.314,2.634,P ＜ 0.05).The occurrence rate of ST segment depression (≥0.10 mV) in leads V2 and V6 were 33.3％ (7/21) and 90.5％ (19/21) in LM group,significantly higher than that in LAD group (11.4％ (4/35) and 62.9 ％ (22/35) ; x2 =3.990,5.105 ;P ＜ 0..05).The start time of ST segment deviation of LM group was significantly earlier than that of LAD group ((199.8 ± 70.8) s vs.(273.7 ± 127.3) s;t =-2.787,P ＜ 0.01).The differences were not statistically significant in terms of the exercise time between groups ((315.0 ± 120.0) s vs.(376.1 ± 110.0) s;t =-1.948;P ＞ 0.05),the rate for achieving target heart rate(33.3％ (7/21) vs.48.6％ (17/35) ; x2 =1.244 ; P ＞ 0.05) and the Duke score ((-11.8 ±7.2) vs.(-8.4 ±6.8) ;t =-1:772;P＞0.05).Conclusion Compare with patients with the LAD disease,ST segment elevation of lead aVR is significantly higher induced by treadmill exercise test in patients with left main disease.Meanwhile,the lead accompanied with ST segment depression is significantly higher,and the start time of ST segment deviation is significantly earlier.

Diagnostic value of treadmill exercise test combined with 24 h dynamic electrocardiogram in patients with coronarv heart disease / 中国综合临床

ObjectiveTo evaluate the value of 24 h dynamic electrocardiogram (DCG) and treadmill exercise testing(TET) in diagnosing coronary heart disease(CHD),and analyze relevant index between coronary arteriography(CAG) and treadmill exercise testing.MethodsOne hundred and forty-nine borderline cases of coronary heart disease were enrolled.Every patient was examined by DCG,TET,and CAG,compared the diagnostic value of TET combined with DCG and TET or DCG alone,and record the increased heart rate during the first minute( △ HRl min) of TET and systolic blood pressure(SBP) recovery.The patients were divided into a CHD group and a non-CHD group according to the results of coronary angiography.ResultsThe sensitivity rate was 78.57％ and specific rate was 70.77％ by means of TET.The sensitivity rate was 61.90％ and specific rate was 66.15％ by means of DCG.The sensitivity rate was 95.23％ ,specific rate was 55.38％,positive predictive value was 73.39％ and negative predictive value was 90.00％ by parallel way of DCG and TET,its sensitivity rate (95.23％) and negative predictive value (90.00％ ) were more than those of DCG or TET alone.The sensitivity rate was 52.38％,specific rate was 95.38％,positive predictive value was 93.62％ and negative predictive value was 60.78％ by serial way of DCG and TET,its specific rate (95.38％) and positive predictive value (93.62％ ) were more than those of DCG or TET alone.The number of men in the CHD group was higher than the number of women.Ratio of systolic blood pressure recovery(rSBPR) in the CHD group was significantly higher than that in the non-CHD group ( P ＜ 0.01 ).Conclusion It can obviously enhance the sensitivity rate and specific rate if combined TET with DCG.Patients with CHD have a delayed decline in SBP during recovery which can be one of the indexes to estimate the extent of myocardial ischemia and coronary artery lesion.

Early Treadmill Exercise Testing for Acute Myocardial Infarction: 36 Cases Report / 中国康复理论与实践

@#ObjectiveTo investigate the safety and clinical value of treadmill exercise testing for the patients with acute myocardial infarction in the early recovery. Methods36 patients with acute myocardial infarction performed treadmill exercise testing with Bruce protocol 15～57 d after infarction. ResultsThe outcome of 19 cases was positive, and the outcome of other 16 cases was negative. 1 case couldn't finish the testing, whose outcome could not be analyzed because his exercise time was too short. The average cardic fuction was (5.42±3.12) METs. ConclusionIt is safe that the patients with acute myocardial infarction performed treadmill exercise testing early.