A novel scoring system for stroke risk stratification in Japanese patients with low CHADS2 scores: Study using a transesophageal-echocardiogram endpoint.

BACKGROUND: Catheter ablation is an effective treatment for atrial fibrillation (AF), but it carries risk of perioperative thromboembolism even in cases with low CHADS2 scores. Here, we examined whether a combination of clinical variables can predict stroke risk factors that are assessed by transesophageal echocardiography (TEE). METHODS: The study population consisted of 209 consecutive AF patients with a CHADS2 score of 0 or 1 (58.7 ± 10.6 years old; persistent AF, 33.0%). All patients underwent TEE, and TEE-determined stroke risk (TEE risk) was defined as cardiac thrombus/sludge, dense spontaneous echo contrast (SEC), and/or peak left atrial appendage (LAA) flow velocity <0.25 m/s. RESULTS: Transesophageal echocardiography risk was observed in 10.5% of the patients. In multivariate logistic analysis, persistent AF [odds ratio (OR): 11.5, CI: 3.14-42.1, P = .0002], left atrial diameter (LAD) (OR: 1.10, CI: 1.01-1.20, P = .0293), contrast medium defect (CMD) in the LAA detected by computed tomography (OR: 20.2, CI: 6.3-65.0, P < .0001), and serum brain natriuretic peptide (BNP) level (OR: 1.00, CI: 1.00-1.01, P = .0056) were independent predictors of TEE risk. A new scoring system comprising LAD > 41 mm (1 point), BNP > 47 pg/mL (1 point), CMD (2 points), and persistent AF (2 points) was constructed and defined as TEE-risk score. The area under the curve (AUC) for prediction of TEE risk was 0.631 in modified CHADS2 score and it was 0.852 in TEE-risk score. CONCLUSION: Transesophageal echocardiography risk is predictable by TEE-risk score, and its combination with CHADS2 score may improve the stroke risk stratification in AF patients with a low CHADS2 score.

Predictors of appropriate ICD therapy in Japanese patients with structural heart diseases: A major role of prior sustained ventricular tachycardia in secondary prevention.

BACKGROUND: Implantable cardioverter defibrillator (ICD) and cardiac resynchronization with a defibrillator (CRT-D) are established therapies for secondary prevention of sudden cardiac death (SCD) in patients with structural heart disease (SHD), but the rates of subsequent ICD/CRT-D therapy widely differ among patients with SHD. The aim of this study was to determine clinical factors associated with appropriate therapy for preventing SCD in patients with SHD. METHODS: We enrolled 147 patients with SHD (mean age, 59 ± 15 years; mean ejection fraction [EF], 45 ± 15%) who underwent ICD/CRT-D implantation for secondary prevention of SCD (ischemic heart disease, n = 50; nonischemic heart disease, n = 97). ICD/CRT-D was implanted for aborted cardiopulmonary arrest (CPA, n = 65) or sustained ventricular tachycardia (VT, n = 82). RESULTS: During a follow-up period of 3.2 ± 3.6 years, 79 of the 147 patients had appropriate ICD/CRT-D therapies. A Kaplan-Meier survival curve showed that the rate of appropriate therapy was 54% at 5-year follow-up. Prior sustained VT, lower EF, and use of a class I antiarrhythmic drug were significantly more frequent in patients with appropriate therapy. In multivariate analysis, prior sustained VT (hazard ratio, 2.8; 95% CI, 1.60-4.46; P = .001) was the only independent predictor for appropriate ICD/CRT-D therapy. Kaplan-Meier survival curves showed that rates of appropriate therapy during a 5-year follow-up period were 70% and 34% in patients with sustained VT and those with CPA, respectively (P = .001). CONCLUSIONS: In SHD patients implanted with an ICD/CRT-D, prior sustained VT as an indication of ICD/CRT-D implantation, but not EF or an antiarrhythmic drug, predicts a high rate of appropriate therapy.

Left atrial strain assessed by three-dimensional speckle tracking echocardiography predicts atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: Several studies have shown the utility of left atrial (LA) function determined by two-dimensional or three-dimensional speckle tracking echocardiography (2D- or 3D-STE) for identifying patients with paroxysmal atrial fibrillation (AF). However, whether 3D-STE is applicable for prediction of the recurrence of AF after catheter ablation (CA) remains unknown. We examined whether any 3D-STE parameters are better than 2D-STE parameters for the prediction of AF recurrence. METHODS: Forty-two patients with paroxysmal AF (58 ± 10 years old, 69% male) underwent 2D- and 3D-STE within 3 days before first-time CA. The global peak LA longitudinal, circumferential, and area strains during systole (3D-GLSs, -GCSs, and -GASs, respectively) and those just before atrial contraction (3D-GLSa, -GCSa, and -GASa, respectively) were determined by 3D-STE and standard deviations of times to peaks of regional LA strains were calculated as indices of LA dyssynchrony. In 2D-STE, global LA longitudinal strains during systole and just before atrial contraction (2D-GLSs and -GLSa) were determined. RESULTS: During follow-up of 441 ± 221 days, 12 patients (29%) had AF recurrence. In the univariate Cox proportional hazard analysis, age [hazard ratio (HR): 1.08, p = 0.04], 3D-GCSs (HR: 0.91, p = 0.03), and 3D-GASs (HR: 0.95, p = 0.01) were predictors of AF recurrence, though associations of recurrence with 2D-STE parameters, indices of LA synchrony, and LA volume were not significant. Multivariable analysis showed that 3D-GASs was an independent predictor of AF recurrence (HR: 0.96, p = 0.048). CONCLUSIONS: LA strain determined by 3D-STE is a novel and better predictor of AF recurrence after CA than that determined by 2D-STE or other known predictors.

Clinical impact of myocardial mTORC1 activation in nonischemic dilated cardiomyopathy.

BACKGROUND: Activity of mTOR complex 1 (mTORC1) has been shown to be up-regulated in animal models of heart failure. Here, we investigated the change and role of mTORC1 in human nonischemic dilated cardiomyopathy (NICM). METHODS: Endomyocardial biopsy specimens were obtained from patients with NICM (n=52) and from Brugada syndrome patients with normal LVEF as controls (n=10). The specimens were stained for phospho-ribosomal protein S6 (p-Rps6) and phospho-p70S6K (p-p70S6K), and the area with p-Rps6 signal was used as an index of mTORC1 activity. Using median mTORC1 activity, patients were divided into a high mTORC1 activity (H-mTOR) group and a low mTORC1 activity (L-mTOR) group. RESULTS: The ratio of p-Rps6-positive area in biopsy samples was 10-fold larger in patients with NICM than in controls (2.0±2.2% vs. 0.2±0.2%, p<0.01). p-p70S6K signal level was higher in the H-mTOR group than in the L-mTOR group. The proportion of patients with a family history of cardiomyopathy was higher and the proportion of patients on ACE inhibitors or angiotensin receptor blockers was lower in the H-mTOR group than in the L-mTOR group. The p-Rps6-positive area was correlated with extent of myocardial fibrosis (r=0.46, p<0.01). The cardiac event-free survival rate during a 5-year follow-up period tended to be lower in the H-mTOR group than in the L-mTOR group (52.9% vs. 81.6%, P=0.10). CONCLUSION: Aberrant activation of mTORC1 in cardiomyocytes was associated with myocardial fibrosis and a trend for worse prognosis in patients with NICM, indicating that persistently activated mTORC1 contributes to progression of human heart failure.

Cardiac tamponade leading to the diagnosis of eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome): a case report and review of the literature.

Eosinophilic granulomatosis with polyangiitis (EGPA), which was previously called Churg-Strauss syndrome, is a necrotizing systemic vasculitis of unknown cause accompanied by prominent eosinophilia. Cardiovascular complications, including eosinophilic myocarditis, are a major cause of mortality in this disorder. Acute pericarditis with slight pericardial effusion is a typical manifestation in EGPA, though hemodynamically significant pericardial effusion has been reported in a few cases. We report a case that initially presented with isolated cardiac tamponade, which was followed by systemic manifestations of EGPA over 3 weeks. Including the present case, previous EGPA cases with cardiac tamponade are reviewed to delineate its clinical characteristics.

"Ballooning" patterns in takotsubo cardiomyopathy reflect different clinical backgrounds and outcomes: a BOREAS-TCM study.

Whether different patterns of ventricular ballooning in takotsubo cardiomyopathy (TCM) reflect differences in trigger mechanisms or clinical outcomes is unclear. Here we examined differences in the clinical characteristics of typical and atypical forms of TCM. TCM patients (n = 251) in the BOREAS Registry were enrolled for comparison of TCM with apical ballooning (type A, n = 217) and TCM with non-apical ballooning (type non-A, n = 34). The percentage of females was significantly lower in the type non-A group (58.8 vs. 75.6 %), while other demographic parameters and triggers of TCM were similar in the two groups. Rate of mid-ventricular obstruction (MVO) was lower (2.9 vs. 14.3 %) in the type non-A group than in the type A group, though left ventricular ejection fractions in the two groups were comparable. During a follow-up period of 2.6 ± 2.8 years, TCM recurred in 2.9 % of the patients and cardiac death occurred in 4.0 %. Cox proportional hazard analysis indicated that body mass index (hazard ratio [HR]: 0.75, 95 % confidence interval [CI] 0.54-0.99) and MVO (HR: 14.71, CI 1.87-304.66) were determinants of TCM recurrence and that advanced age (HR: 1.09, CI 1.02-1.17) and cardiogenic shock (HR: 4.27, CI 1.07-18.93) were significantly associated with cardiac death. In conclusion, approximately 20 % of TCM patients show non-apical left ventricular ballooning, and female sex and MVO are less frequent in this type than in apical ballooning type TCM. Low body mass index and MVO are risk factors of recurrence, and advanced age and cardiogenic shock are risk factors of cardiac death in TCM.

Efficacy of anti-tachycardia pacing for terminating fast ventricular tachycardia in Japanese implantable cardioverter defibrillator patients. Primary results of the SATISFACTION study.

BACKGROUND: Anti-tachycardia pacing (ATP) delivered by implantable cardioverter defibrillators (ICD) safely avoids painful shocks with minimum risk of tachycardia acceleration. The etiology of ventricular tachycardia (VT) in those studies, however, was predominantly coronary artery disease (CAD). Patient etiology differs by geography and could affect ATP efficacy rate. The primary objective of this study was to examine how often the first ATP therapy terminates fast VT (FVT) in Japanese ICD patients with regional etiologies. METHODS AND RESULTS: Seven hundred and fifteen patients received ICD or cardiac resynchronization therapy defibrillator with the function of ATP during capacitor charging. The primary endpoint was the first ATP success rate for terminating FVT with cycle length 240-320 ms. During a mean follow-up of 11.3 months, 888 spontaneous VT episodes were detected, including 276 FVT (31.1%) in 42 patients. The first-ATP success rate for FVT in the overall group (41% CAD, 59% non-CAD including 23% idiopathic VT) was 62.1% (61.7% adjusted). Success rate was not different between non-CAD and CAD patients (61.4% adjusted and 57.5% adjusted, respectively, P=0.75). Eight FVT episodes (2.9%) accelerated after the first ATP attempt, all of which were terminated by subsequent device therapy (additional ATP or shock). CONCLUSIONS: ATP efficacy for FVT was similar between ICD patients with and without CAD etiology.

[Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation].

BACKGROUND: In CARTOMERGE(®) for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. PURPOSE: To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. METHODS: The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. RESULTS: Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. CONCLUSIONS: Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time.

Assessment of left atrial deformation and synchrony by three-dimensional speckle-tracking echocardiography: comparative studies in healthy subjects and patients with atrial fibrillation.

BACKGROUND: The aim of this study was to examine whether left atrial (LA) strain and synchrony can be assessed using three-dimensional (3D) speckle-tracking echocardiography (STE) and how 3D STE parameters are modified by atrial fibrillation (AF). METHODS: LA peak ventricular systolic longitudinal strain (LSs), circumferential strain (CSs), and area strain (ASs) and LA peak pre-atrial contraction longitudinal strain, circumferential strain (CSa), and area strain were determined using 3D STE, and SDs of times to peaks of regional LA strain were calculated as indices of LA dyssynchrony. Three-dimensional speckle-tracking was able to measure LA strain in 75 of the 77 healthy subjects and in all 47 patients with AF (31 with paroxysmal AF [PAF] and 16 with permanent AF). RESULTS: The mean time for analysis with 3D STE was 18% shorter than with two-dimensional (2D) STE (P < .05). On 3D STE, values of interobserver and intraobserver variability of LA strain were <10% and <12%, respectively. LSs, CSs, ASs, and 2D STE LSs were reduced in patients with PAF compared with controls, and further reductions of these parameters were observed in patients with permanent AF. SDs of LSs, CSs, and ASs were similarly larger in patients with PAF and in those with permanent AF compared with controls. Patients with PAF showed smaller LA peak pre-atrial contraction longitudinal strain, CSa, and LA peak pre-atrial contraction area strain and larger SDs of CSa and LA peak pre-atrial contraction area strain compared with controls. In multivariate analysis, 2D STE LSs (P = .044), LSs (P = .040), ASs (P = .007), and CSa (P = .020) were independent predictors of PAF. CONCLUSIONS: Three-dimensional speckle-tracking enables the measurement of both LA strain and synchrony with excellent reproducibility. Three-dimensional LA strain appears to be beneficial compared with 2D LA strain for identifying patients with PAF.

Left ventricular hypertrophy causes different changes in longitudinal, radial, and circumferential mechanics in patients with hypertension: a two-dimensional speckle tracking study.

BACKGROUND: Systolic reserve is an important compensatory mechanism against increasing afterload. Although longitudinal systolic dysfunction with preserved ejection fraction has been reported in hypertensive hearts, radial and circumferential function has not been fully examined. The aim of this study was to investigate three-directional systolic function and its relationships with left ventricular geometry in asymptomatic hypertensive patients using two-dimensional speckle-tracking imaging. METHODS: Echocardiographic evaluations were performed in 74 hypertensive patients and 55 age-matched control subjects. RESULTS: Longitudinal strain was significantly reduced in the hypertrophy groups compared with that in control subjects (concentric, -15.1 ± 4.0%; eccentric, -15.9 ± 4.4%; control, -18.9 ± 3.3%; P < .05). Conversely, radial strain was significantly higher in the normal geometry group than in control subjects (53.8 ± 19.4% vs 40.3 ± 15.1%, P < .05). However, this augmentation was attenuated in the other geometries. CONCLUSION: Hypertrophic remodeling attenuates compensatory augmentation of radial systolic function and is associated with latent longitudinal systolic dysfunction.

Impaired cardiac sympathetic innervation and myocardial perfusion are related to lethal arrhythmia: quantification of cardiac tracers in patients with ICDs.

UNLABELLED: Despite widespread prophylactic use of implantable cardioverter defibrillator (ICD) therapy, sudden cardiac death and refractory arrhythmia events are still important clinical issues to be overcome. We examined whether the impairment of cardiac sympathetic innervation and myocardial perfusion is responsible for lethal arrhythmic events and has prognostic value by comparing conventional clinical indices. METHODS: In consecutive ICDs implanted in 60 patients, cardiac uptake of (123)I-metaiodobenzylguanidine and (99m)Tc-tetrofosmin at rest was quantified, and then patients were prospectively followed with endpoints of appropriate ICD shocks or cardiac death. Cardiac metaiodobenzylguanidine activity was quantified as a heart-to-mediastinum ratio (HMR), and impaired tetrofosmin uptake was graded as a summed score (SS) using a computerized technique with a percentage of tracer uptake. RESULTS: During a mean 29-mo interval, ICD shock was documented in 30 patients (50%); 3 cardiac deaths were also observed in this group of patients. Patients with ICD shocks had a significantly smaller HMR and a greater SS than did those without (1.73 +/- 0.34 vs. 2.06 +/- 0.46, P = 0.003, and 18.0 +/- 16.2 vs. 5.7 +/- 4.4, P = 0.001, respectively). Kaplan-Meier analysis showed that patients who had both an HMR of 1.90 or less and an SS of 12 or greater had a significantly greater ICD discharge rate than did those who had both an HMR greater than 1.90 and an SS less than 12 (94% vs. 18%, P < 0.005) (log rank, 15.14; P < 0.0005). Multivariate analysis with a Cox model identified the greatest Wald chi(2) of 6.454 and a hazard ratio of 3.857 (P = 0.011) when an HMR of 1.9 or less and tetrofosmin SS of 12 or greater were combined. CONCLUSION: Impairment of cardiac sympathetic innervation and myocardial perfusion is related to lethal arrhythmic events leading to sudden death, and the combined assessment of these can identify patients for whom prophylactic ICD use has the greatest potential.

Prognostic implications of left atrial dilation evaluated by echocardiographic volume in patients with normal left atrial antero-posterior dimensions.

BACKGROUND: The purpose of this study was to clarify the clinical characteristics and prognostic implications of left atrial (LA) dilation evaluated echocardiographic volume in patients with normal LA dimension (LAD). METHODS: A total of 140 consecutive patients (81 men, mean age: 57 ± 18 years) with normal LAD (<39 mm for women and <41 mm for men) who underwent conventional echocardiography and tissue Doppler imaging were enrolled. LA volume (LAV) ≥29 ml/m(2) was defined as abnormal LAV. Hospitalization for heart failure (HF) and cardiac death were defined as cardiac events. RESULTS: Eighty-seven (62%) of the patients had LA dilation, defined as a normal LAD but an abnormal LAV. Patients with LA dilation were significantly older and had a significantly higher left ventricular (LV) mass index (LVMI) and incidences of hypertension and HF than did patients with both normal LAD and normal LAV. Logistic regression analysis revealed that increased LVMI was an independent (p < 0.01) determinant of LA dilatation. During a follow-up period of 16 ± 10 months, ten patients had cardiac events. Patients with cardiac events had a higher incidence of LA dilation than those without cardiac events (100 vs. 59%, p < 0.05). A Kaplan-Meier survival curve showed that patients with LA dilation had a significantly lower survival rate than those with both normal LAD and normal LAV (log rank 6.1, p = 0.014). CONCLUSIONS: LV hypertrophy is an independent determinant of LA dilation in patients with normal LAD. Assessment of LA morphology using LAV can contribute to risk stratification in patients with normal LAD.

Clinical implications of midventricular obstruction and intravenous propranolol use in transient left ventricular apical ballooning (Tako-tsubo cardiomyopathy).

BACKGROUND: Persistent hypotension with dynamic midventricular obstruction (MVO) in patients with transient left ventricular (LV) apical ballooning (Tako-tsubo cardiomyopathy) is an important complication that needs to be treated. PURPOSE: The objective of this study is to determine the effects of intravenous propranolol challenge on MVO in transient LV apical ballooning. SUBJECTS AND METHODS: Thirty-four patients (12 males, 22 females, mean age 64 +/- 17 years, age range 22-84 years) with LV apical ballooning were enrolled. The hemodynamic and echocardiographic effects of propranolol (0.05 mg/kg, maximum 4 mg) were analyzed in 13 patients. RESULTS: (1) Midventricular obstruction was present in 8 (24%) of 34 patients, and the pressure gradient (PG) ranged from 28 to 140 mm Hg. (2) Patients with MVO had similar demographic and clinical characteristics (symptoms, peak creatine kinase, plasma catecholamine levels) as those without MVO; however, in patients with MVO, abnormal Q waves on electrocardiogram and hypotension were more prevalent. (3) In the MVO group, intravenous propranolol changed the PG from 90 +/- 42 to 22 +/- 9 mm Hg, the systolic blood pressure (SBP) from 85 +/- 11 to 116 +/- 20 mm Hg, and the LV ejection fraction (LVEF) from 30% +/- 7% to 43% +/- 4%. (4) In all subjects, the changes in the PG after propranolol injection had a significant linear correlation with the SBP and LVEF changes: deltaSBP = 4.738 + 0.315 x deltaPG (r = 0.689 (P < .001) and deltaLVEF = 2.973 + 0.1321 x deltaPG (r = 0.715, P < .001). CONCLUSION: Intravenous propranolol is useful for treating dynamic MVO in patients with transient LV apical ballooning.

Predicting the need for an implantable cardioverter defibrillator using cardiac metaiodobenzylguanidine activity together with plasma natriuretic peptide concentration or left ventricular function.

UNLABELLED: Despite widespread use of implantable cardioverter defibrillators (ICDs), their cost and the fact that only a certain group of patients fully benefits from the devices require appropriate risk stratification of patients. This study investigated whether altered cardiac autonomic function is associated with the occurrence of ICD discharge or lethal cardiac events. METHODS: Fifty-four ICD-treated patients were prospectively followed after assessment of cardiac metaiodobenzylguanidine (MIBG) activity, quantified as the heart-to-mediastinum ratio (HMR), plasma concentration of brain natriuretic peptide (BNP), and left ventricular ejection fraction (LVEF). Patients were divided into 2 groups based on the presence (group A, n = 21) or absence (group B, n = 33) of appropriate ICD discharge during a 15-mo period. RESULTS: Group A had a significantly lower level of MIBG activity and a higher plasma BNP level than did group B. Univariate analysis revealed BNP level, any medication, and late HMR to be significant predictors, and multivariate analysis showed late HMR to be an independent predictor. An HMR of less than 1.95 with a plasma BNP level of more than 187 pg/mL or an LVEF of less than 50% had significantly increased power to predict ICD shock: positive predictive values, 82% (HMR + BNP) and 58% (HMR + LVEF); negative predictive values, 73% (HMR + BNP) and 77% (HMR + LVEF); sensitivities, 45% (HMR + BNP) and 67% (HMR + LVEF); and specificities, 94% (HMR + BNP) and 70% (HMR + LVEF). CONCLUSION: When combined with plasma BNP concentration or cardiac function, cardiac MIBG activity is closely related to lethal cardiac events and can be used to identify patients who would benefit most from an ICD.

Long-term outcome after primary stenting versus balloon angioplasty for acute myocardial infarction.

The objective of the present prospective multicenter case-control study was to investigate the long-term clinical outcome (5 years) of primary stenting compared to primary percutaneous transluminal coronary angioplasty (PTCA) without stenting (POBA) in patients with acute myocardial infarction at 7 cardiovascular centers in Hokkaido, Japan. Forty-one patients with acute myocardial infarction treated with successful primary stenting (stent group: case) and paired with 41 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting (POBA group: control) were analyzed. After 1 year, the stent group had a lower incidence of the combined clinical endpoint (death, rehospitalization due to congestive heart failure, nonfatal myocardial infarction, repeat angioplasty, CABG, or cerebrovascular events) compared to the POBA group (17.1% versus 39.0%, P = 0.049). After 5 years, the incidences of congestive heart failure and cardiac death were the same in both groups. However, compared to the POBA group, the stent group had a lower combined clinical endpoint (34.1% versus 61.0%, P = 0.027). The Kaplan-Meier event-free survival curves of the stent group showed a significantly lower occurrence of clinical events compared to the POBA group (P = 0.0116). Multiple logistic regression analysis of clinical events identified age > or = 69 years (P = 0.0092, odds ratio = 4.179) and stenting (P = 0.0158, odds ratio = 0.279) as explanatory factors. Compared with POBA, primary stenting for acute myocardial infarction results in a better long-term clinical outcome.

Diagnostic implications of modified treadmill and head-up tilt tests in exercise-related syncope: comparative studies with situational and/or vasovagal syncope.

BACKGROUND: The precise pathophysiological basis of exercise-related vasodepressor syncope is not well understood. PURPOSE: The diagnostic values of head-up tilt and modified treadmill tests with abrupt termination were tested in patients with exercise-related syncope and compared with those of patients with situational or vasovagal syncope. PATIENTS AND METHODS: Diagnostic accuracies of head-up tilt and modified treadmill exercise tests were examined in 44 patients with unexplained syncope (26 men, 18 women, aged 46 19 years) and in 20 control subjects. Results for 18 patients with syncope during exercise (short-distance dash [n=7], jogging [n=3], going up stairs [n=6], swimming [n=1] or cycling [n=1]), defined as exercise-related syncope, were compared with those for 26 patients with exercise-unrelated syncope (including situational [n=7] and vasovagal [n=14] syncope). RESULTS: No differences were found between the clinical backgrounds of subjects with and those without exercise-related syncope. Head-up tilt testing had good diagnostic sensitivities, specificities and accuracies in both exercise-related and exercise-unrelated groups (84% versus 77%, 84% versus 85%, 84% versus 80%, respectively). The corresponding values of modified treadmill tests in the two groups were 78% versus 19% (P<0.05), 95% versus 95% and 86% versus 52% (P<0.05), respectively. The results of exercise tests were of limited diagnostic value for exercise-unrelated syncope. Beta-blockade had good short term efficacy in subjects with exercise-related syncope (nine of 15, 60%) as well as in subjects with exercise-unrelated syncope (seven of 10, 70%). CONCLUSIONS: Modified treadmill exercise testing is thought to be useful for diagnosing exercise-related syncope.