Left atrial strain analysis and new-onset atrial fibrillation in patients with ST-segment elevation myocardial infarction: A prospective echocardiography study.

BACKGROUND: New-onset atrial fibrillation (NOAF) is a well-known complication of ST-segment elevation myocardial infarction (STEMI), probably due to left atrial (LA) remodelling. LA strain (LAS) can predict NOAF in several cardiovascular diseases. OBJECTIVE: To assess whether LAS predicts NOAF in sinus rhythm patients with STEMI during hospitalization. METHODS: Adults with a STEMI and transthoracic echocardiography performed within 48hours of admission were included. LAS analysis, performed by automated software, recorded LAS during the reservoir phase (LASr), the conduit phase (LAScd) and the contraction phase (LASct). RESULTS: From May 2021 to November 2022, 175 patients were included, 21 (12%) of whom developed NOAF. NOAF patients were older (median [Q1-Q3]: 67 [59-80] vs 59 [51-67]years; P=0.006) and had a higher Thrombolysis In Myocardial Infarction scores (4 [2-7] vs 3 [1-4]; P=0.005). All LAS parameters were significantly impaired in NOAF patients, especially LASr (13.0% [10.5-28.4] vs 36.6% [29.0-44.9]; P=0.001). An LASr cut-off of 27% had a sensitivity of 81% and a specificity of 80% to identify patients with NOAF. In a multivariable model, LASr was significantly associated with NOAF (odds ratio 1.18, 95% confidence interval 1.09-1.26; P=0.003). The cumulative risk of NOAF during hospital stay was 30% (18-43 with LASr<27% and 4% [1.5-8.5] with LASr≥27% [P<0.0001]). CONCLUSION: NOAF is a frequent complication of STEMI. LASr seems helpful for identifying patients at high risk of NOAF during hospitalization.

Prognostic Value of a New Right Ventricular-to-Pulmonary Artery Coupling Parameter Using Right Ventricular Longitudinal Shortening Fraction in Patients Undergoing Transcatheter Aortic Valve Replacement: A Prospective Echocardiography Study.

Introduction: Right-ventricular-to-pulmonary artery (RV-PA) coupling, measured as the ratio of tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP), has emerged as a predictor factor in patients undergoing transcatheter aortic valvular replacement (TAVR). Right ventricular longitudinal shortening fraction (RV-LSF) outperformed TAPSE as a prognostic parameter in several diseases. We aimed to compare the prognostic ability of two RV-PA coupling parameters (TAPSE/PASP and the RV-LSF/PASP ratio) in identifying MACE occurrences. Method: A prospective and single-center study involving 197 patients who underwent TAVR was conducted. MACE (heart failure, myocardial infarction, stroke, and death within six months) constituted the primary outcome. ROC curve analysis determined cutoff values for RV-PA ratios. Multivariable Cox regression analysis explored the association between RV-PA ratios and MACE. Results: Forty-six patients (23%) experienced the primary outcome. No significant difference in ROC curve analysis was found (RV-LSF/PASP with AUC = 0.67, 95%CI = [0.58-0.77] vs. TAPSE/PASP with AUC = 0.62, 95%CI = [0.49-0.69]; p = 0.16). RV-LSF/PASP < 0.30%.mmHg-1 was independently associated with the primary outcome. The 6-month cumulative risk of MACE was 59% (95%CI = [38-74]) for patients with RV-LSF/PASP < 0.30%.mmHg-1 and 17% (95%CI = [12-23]) for those with RV-LSF/PASP ≥ 0.30%.mmHg-1; (p < 0.0001). Conclusions: In a contemporary cohort of patients undergoing TAVR, RV-PA uncoupling defined by an RV-LSF/PASP < 0.30%.mmHg-1 was associated with MACE at 6 months.

Prognostic Value of Right Ventricular Longitudinal Shortening Fraction in Patients With ST-Elevation Myocardial Infarction: A Prospective Echocardiography Study.

Right ventricular systolic dysfunction (RVsD) frequently occurs in patients with ST-elevation myocardial infarction (STEMI). However, the diagnosis depends on the echocardiographic parameters to define RVsD. The right ventricle longitudinal shortening fraction (RV-LSF) is an accurate and reproducible 2-dimensional speckle-tracking parameter associated with clinical events in various pathologies. This study aimed to evaluate the association between RVsD and major adverse cardiovascular event (MACE) occurrence in a cohort of patients with STEMI. Adult patients with STEMI admitted to Amiens University Hospital's cardiovascular intensive care unit between May 2021 and November 2022 who underwent coronary angiography and transthoracic echocardiography within 48 hours of admission were included. RVsD was defined as RV-LSF <20%. The primary outcome was MACE occurrence, including heart failure, myocardial infarction, stroke, and death within 6 months of admission. A multivariable Cox regression analysis with proportional hazard ratio models assessed the association between RVsD and MACEs. In the 164 included patients, 72 (44%) had RVsD and 92 (56%) did not. The RVsD group had a significantly higher proportion of MACEs during the 6-month follow-up (n = 23 of 72, 33%) than the group without RVsD (n = 8 of 92, 9%, p = 0.001). RVsD showed an independent association with MACEs at 6 months (hazard ratio 3.1, 95% confidence interval [CI] 1.35 to 7.30, p = 0.008). Left ventricular ejection fraction <40% and Thrombolysis in Myocardial Infarction score >4 were independently associated with RVsD (odds ratio 2.80, 95% CI 1.34 to 5.98 and odds ratio 2.15, 95% CI 1.18 to 4.39, respectively, p = 0.015). The cumulative risk of MACEs at 6 months was 33% for RV-LSF <20% and 9% for RV-LSF ≥20% (log-rank test p <0.001). RVsD, defined by RV-LSF <20%, is associated with an increased risk of MACEs after STEMI.

Two-year prognosis of acute coronary syndrome during the first wave of the coronavirus disease 2019 pandemic.

BACKGROUND: The first wave of the coronavirus disease 2019 pandemic significantly changed behaviour in terms of access to healthcare. AIM: To assess the effects of the pandemic and initial lockdown on the incidence of acute coronary syndrome and its long-term prognosis. METHODS: Patients admitted for acute coronary syndrome from 17 March to 6 July 2020 and from 17 March to 6 July 2019 were included. The number of admissions for acute coronary syndrome, acute complication rates and 2-year rates of survival free from major adverse cardiovascular events or death from any cause were compared according to the period of hospitalization. RESULTS: In total, 289 patients were included. We observed a 30±3% drop in acute coronary syndrome admissions during the first lockdown, which did not recover in the 2months after it was lifted. At 2years, there were no significant differences in the combined endpoint of major adverse cardiovascular events or death from any cause between the different periods (P=0.34). Being hospitalized during lockdown was not predictive of adverse events during follow-up (hazard ratio 0.87, 95% confidence interval 0.45-1.66; P=0.67). CONCLUSIONS: We did not observe an increased risk of major cardiovascular events or death at 2years from initial hospitalization for patients hospitalized during the first lockdown, adopted in March 2020 in response to the coronavirus disease 2019 pandemic, potentially as a result of the lack of power of the study.

Aortic root dilatation in PFO-related cryptogenic stroke: A propensity score-matched analysis.

BACKGROUND: Dilatation of the ascending aorta has an important role in the anatomical conformation of interatrial septum (IAS) especially when a patent foramen ovale (PFO) is present. The aim of the study was to investigate the relationship between ascending aortic dilation and PFO-related cryptogenic stroke in a cohort of cryptogenic strokes. METHODS: It is a retrospective, single-center echocardiographic study assessing aortic root dilatation in 315 consecutive patients with cryptogenic stroke between January 2011 and January 2019. Aortic root dilatation was defined by a diameter of the Valsalva sinuses of the proximal aorta >40 mm. Predictive factors of PFO were assessed by a multivariate analysis. Propensity score matching was applied to account for clinical differences. RESULTS: Of the 315 patients, 68 (22%) had an aortic root dilatation and 167 (53%) had a PFO. In the aortic root dilation group, PFO was more often diagnosed (n = 47/68 [69%], vs n = 120/247 [49%], P = .004). In the PFO group with aortic dilatation, IAS was more mobile (n = 37/47[79%] vs n = 69/120[57%], P < .012) and smaller (2.3 ± 0.5 vs 2.5 ± 0.5 mm, P < .009). On multivariate analysis, aortic root dilatation (OR: 2.6; 95% CI [1.2-5.6]; P = .001) and IAS hypermobility (OR: 5.2 95% CI [2.7-10]; P = .001) were associated with PFO. After propensity matching, aortic root dilatation remained strongly associated with PFO (n = 34/107 [32%] vs 15/107[14%], P = .002). CONCLUSION: Aortic root dilation and IAS hypermobility were strongly associated with PFO-related cryptogenic stroke.

Evaluating IMRT and VMAT dose accuracy: practical examples of failure to detect systematic errors when applying a commonly used metric and action levels.

PURPOSE: This study (1) examines a variety of real-world cases where systematic errors were not detected by widely accepted methods for IMRT/VMAT dosimetric accuracy evaluation, and (2) drills-down to identify failure modes and their corresponding means for detection, diagnosis, and mitigation. The primary goal of detailing these case studies is to explore different, more sensitive methods and metrics that could be used more effectively for evaluating accuracy of dose algorithms, delivery systems, and QA devices. METHODS: The authors present seven real-world case studies representing a variety of combinations of the treatment planning system (TPS), linac, delivery modality, and systematic error type. These case studies are typical to what might be used as part of an IMRT or VMAT commissioning test suite, varying in complexity. Each case study is analyzed according to TG-119 instructions for gamma passing rates and action levels for per-beam and/or composite plan dosimetric QA. Then, each case study is analyzed in-depth with advanced diagnostic methods (dose profile examination, EPID-based measurements, dose difference pattern analysis, 3D measurement-guided dose reconstruction, and dose grid inspection) and more sensitive metrics (2% local normalization/2 mm DTA and estimated DVH comparisons). RESULTS: For these case studies, the conventional 3%/3 mm gamma passing rates exceeded 99% for IMRT per-beam analyses and ranged from 93.9% to 100% for composite plan dose analysis, well above the TG-119 action levels of 90% and 88%, respectively. However, all cases had systematic errors that were detected only by using advanced diagnostic techniques and more sensitive metrics. The systematic errors caused variable but noteworthy impact, including estimated target dose coverage loss of up to 5.5% and local dose deviations up to 31.5%. Types of errors included TPS model settings, algorithm limitations, and modeling and alignment of QA phantoms in the TPS. Most of the errors were correctable after detection and diagnosis, and the uncorrectable errors provided useful information about system limitations, which is another key element of system commissioning. CONCLUSIONS: Many forms of relevant systematic errors can go undetected when the currently prevalent metrics for IMRT∕VMAT commissioning are used. If alternative methods and metrics are used instead of (or in addition to) the conventional metrics, these errors are more likely to be detected, and only once they are detected can they be properly diagnosed and rooted out of the system. Removing systematic errors should be a goal not only of commissioning by the end users but also product validation by the manufacturers. For any systematic errors that cannot be removed, detecting and quantifying them is important as it will help the physicist understand the limits of the system and work with the manufacturer on improvements. In summary, IMRT and VMAT commissioning, along with product validation, would benefit from the retirement of the 3%/3 mm passing rates as a primary metric of performance, and the adoption instead of tighter tolerances, more diligent diagnostics, and more thorough analysis.

Prevalence and prognostic significance of 'J waves' in patients experiencing ventricular fibrillation during acute coronary syndrome.

BACKGROUND: 'J waves' have been associated with idiopathic ventricular fibrillation (VF) and have also been described in patients with ischaemic VF. AIMS: Our aim was to determine whether inferior and/or lateral 'J waves' were associated with the occurrence of VF or in hospital mortality during acute coronary syndrome (ACS). METHODS: Fifty-three patients (mean age 52 ± 10 years) experienced cardiac arrest due to VF during the first 48 hours of an ACS. These patients were entered in a retrospective case-control study. The control group was matched for age and sex and included 106 patients who experienced an ACS but without VF. RESULTS: 'J waves' were more frequent in the study group than in the control group (62% vs. 39%; P=0.006). 'J waves' (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.5-7.1; P=0.001) and left ventricular ejection fraction<40% (53% vs. 14%; P<0.001) (OR 7.9, 95% CI 3.5-18.0; P=0.001) were associated with VF. Inhospital mortality was 15.1% in the study group versus 0.9% in the control group (OR 18.7, 95% CI 2.2-157.5; P=0.008). VF (OR 18.3, 95% CI 2.3-835.9; P<0.001) and the presence of 'J waves' (OR 15.9. 95% CI 2.4-∞; P<0.001) were predictive of inhospital mortality. In patients who experienced VF, inhospital mortality was 24% when 'J waves' were observed and 0% when 'J waves' were absent (P=0.02). CONCLUSIONS: Inferior and lateral 'J waves' were observed more frequently in patients who experienced cardiac arrest due to VF associated with ACS than in the absence of cardiac arrest and were associated with higher inhospital mortality.

Normal pulmonary veins anatomy is associated with better AF-free survival after cryoablation as compared to atypical anatomy with common left pulmonary vein.

BACKGROUND: Pulmonary vein cryoablation (PVC) is a new approach in the treatment of recurrent atrial fibrillation (AF). Computed tomography (CT) can be used to evaluate the left atrium anatomy and PVs dimensions to facilitate the procedure. In radiofrequency procedures, some anatomic variants such as common left (CLPV) or right (CRPV) PV were reported as factors associated with technical procedure difficulties and potential long-term complications. We hypothesized that the absence of CLPV as determined by CT would predict better AF-free survival after PVC. METHODS AND RESULTS: We included 118 consecutive patients (mean age 56 ± 10 years; 77% males) with drug refractory paroxysmal (72%)/persistent (28%) AF, with more than 6 months follow-up, who underwent PVC. On CT scanning images performed within 1 month prior to ablation, we evaluated PV anatomic patterns: presence of CLPV or CRPV. Each patient was evaluated by 24-hour Holter monitoring within 1 and 3 months and all patients were periodically evaluated at 1, 3, and 6 months, and every 6 months thereafter. Patients were asked to record their 12-lead electrocardiogram whenever they experienced symptoms suggestive of AF. Recurrence was defined as AF that lasted at least 30 seconds. CLPV was present in 30 (25%) patients and no patients with CRPV were identified. At the end of the 13 months follow-up, patients with normal PVs had significantly better AF-free survival compared to patients with CLPV (67% vs 50%, P = 0.02). The difference was present in patients with paroxysmal AF (P = 0.008) but not in patients with persistent AF (P = 0.92). CONCLUSION: In patients undergoing cryoballoon PV isolation for AF, the presence of normal PVs pattern is associated with better AF-free survival as compared to atypical PV anatomy with CLPV, particularly in patients with paroxysmal AF.

Dual balloon size strategy for cryoisolation of the pulmonary veins in patients with atrial fibrillation: comparison of 23 and 28mm diameter cryoballoons.

BACKGROUND: Systematic use of a 28mm balloon has been proposed for pulmonary vein cryoisolation in patients with atrial fibrillation. OBJECTIVE: To assess the results of a dual balloon size strategy using a 23 or 28mm cryoballoon catheter for pulmonary vein isolation. METHODS: A total of 118 patients (mean age 56 ± 10 years) with paroxysmal (n=85) or persistent atrial fibrillation (n=33) were enrolled. Patients with four pulmonary veins<20mm in diameter were isolated with a 23mm cryoballoon (n=29); patients with one pulmonary vein diameter ≥20mm were isolated with a 28mm cryoballoon (n=89). RESULTS: No significant difference in procedural variables was observed between the two groups. AF-free survival, after a mean follow-up of 19.9 ± 5 months, was similar in the two groups (69% vs 62%; p=0.57 and between patients with paroxysmal atrial fibrillation (68% vs 68%; p=0.91) or persistent AF (75% vs 48%; p=0.60). AF duration before the ablation procedure (p=0.005) was an independent predictor of AF recurrence. Phrenic nerve palsy rate was not statistically different in the two groups (4 [14%] vs 9 [10%]; p=0.73). The temperature in the right superior pulmonary vein (p=0.008) was an independent predictor of phrenic nerve palsy. Five patients developed left atrial flutter with the 28mm diameter balloon versus none with the 23mm balloon. CONCLUSIONS: A dual balloon size strategy was not associated with a lower AF-free survival or a higher procedure-related complication rate in patients in whom the 23mm balloon was used. Pulmonary vein isolation with a 23mm cryoballoon catheter appears to be an appropriate option in selected patients with small pulmonary vein diameters.

Communicating bilateral coronary artery to pulmonary artery fistula with aneurysm in asymptomatic patient: successful conservative management with selective coil embolization of the aneurysm.

Congenital coronary artery fistula (CAF) is a rare disease. We report a case of a 58-year-old man having a complex coronary to pulmonary artery fistula associated with a large saccular aneurysm originated from the terminal portion of the right coronary artery. An endovascular approach was adopted in order to prevent aneurysmal rupture without need of complete closure of the fistula. We suggest transcatheter embolization as an alternative technique for aneurysmal formation closure in asymptomatic patients with complex CAF complicated with aneurysmal formation if it is not necessary to obtain a complete CAF closure.

Ajmaline challenge for the diagnosis of Brugada syndrome: which protocol?

BACKGROUND: Ajmaline challenge is commonly used for the diagnosis of Brugada syndrome. A slow infusion rate has been recommended in view of the proarrhythmic risk, but the diagnostic value of various infusion rates has not been investigated. AIMS: To compare rapid and slow ajmaline infusion rates and to assess the proarrhythmic risk. METHODS: The first part of this study prospectively compared rapid and slow infusion rates in terms of results and ventricular arrhythmias. Thirty-two patients (mean age 41±12 years; 26 men) received the two ajmaline challenges on different days. According to randomization, ajmaline (1 mg/kg) was infused at 1 mg/sec or over 10 minutes. The second part of the study retrospectively assessed the prevalence of ventricular arrhythmia during 386 challenges performed at a rapid infusion rate. RESULTS: No differences were observed between rapid and slow tests. All patients diagnosed as positive or negative with one test obtained the same result with the other test. Ventricular premature beats were observed in five of 32 patients during the slow challenge and in four of 32 patients during the rapid challenge. No sustained ventricular arrhythmias were observed. Analysis of the 386 tests revealed four episodes of ventricular arrhythmia (two complex ventricular premature beats, one non-sustained ventricular tachycardia and one ventricular fibrillation). CONCLUSION: Slow and rapid infusions of ajmaline have identical diagnostic performances on suspected Brugada electrocardiograms. Owing to the risk of severe proarrhythmia, a slow infusion rate, allowing early discontinuation, should be recommended.

Prospective evaluation of the familial prevalence of the brugada syndrome.

The familial prevalence of Brugada syndrome (BrS) in a consecutive series of patients was prospectively determined. BrS is genetically determined with autosomal dominant transmission. The familial prevalence of the BrS is unknown. A detailed pedigree of each family of patients with BrS was assembled and permission was obtained to invite relatives for electrocardiography and an ajmaline challenge. Sixty-two of 98 patients participated in the study and were included over a 6-year period. SCN5A genotyping was performed in 56 of these 62 patients (90%). Electrocardiograms (ECGs) of 488 relatives (mean age 38 ± 20 years, 45% men) were recorded and 270 of these relatives agreed to undergo an ajmaline challenge. Spontaneous type 1 BrS ECG was found in 4 of 488 relatives (0.8%). In the group of relatives in whom ajmaline challenge was performed (n = 270), the finding was positive in 79 subjects (29%). SCN5A genotyping identified 5 other affected relatives. As a result, the total number of affected relatives was 88. Standard 12-lead ECG was normal in 64 of the 88 affected relatives (73%). Mean percentage of affected relatives per family was 27 ± 32% (95% confidence interval 19 to 35). Familial forms of BrS were observed in 41 of the 62 families (66%) and no SCN5A mutations were found in sporadic forms. In conclusion, after active family screening affected relatives were found in almost 1/3 of subjects. BrS appeared to be a familial disease in 2/3 of subjects.

Quantification of aortic valve area with ECG-gated multi-detector spiral computed tomography in patients with aortic stenosis and comparison of two image analysis methods.

Thirty-three consecutive patients with aortic stenosis underwent a 16-row spiral CT scan. Aortic valve planimetry was performed using two methods: double-oblique reformation (DO) and 2D-curved multiplanar reconstruction using advanced vessel analysis software (VA). The mean aortic valve area determined by transthoracic echocardiography was 0.88+/-0.34 [0.53-1.88] and did not differ significantly from that determined by CT (DO): 0.87+/-0.38 [0.42-1.93] (p=0.75) or CT (VA): 0.87+/-0.38 [0.44-2.00] (p=0.69). This study demonstrates that 16-row spiral CT scan is a feasible, accurate and reproducible method for aortic valve planimetry in patients with aortic stenosis. Both methods show similar accuracy but the VA method takes slightly longer.

Patient-specific dosimetry of conventional and intensity modulated radiation therapy using a novel full Monte Carlo phase space reconstruction method from electronic portal images.

Electronic portal imagers have promising dosimetric applications in external beam radiation therapy. In this study a patient dose computation algorithm based on Monte Carlo (MC) simulations and on portal images is developed and validated. The patient exit fluence from primary photons is obtained from the portal image after correction for scattered radiation. The scattered radiation at the portal imager and the spectral energy distribution of the primary photons are estimated from MC simulations at the treatment planning stage. The patient exit fluence and the spectral energy distribution of the primary photons are then used to ray-trace the photons from the portal image towards the source through the CT geometry of the patient. Photon weights which reflect the probability of a photon being transmitted are computed during this step. A dedicated MC code is used to transport back these photons from the source through the patient CT geometry to obtain patient dose. Only Compton interactions are considered. This code also produces a reconstructed portal image which is used as a verification tool to ensure that the dose reconstruction is reliable. The dose reconstruction algorithm is compared against MC dose calculation (MCDC) predictions and against measurements in phantom. The reconstructed absolute absorbed doses and the MCDC predictions in homogeneous and heterogeneous phantoms agree within 3% for simple open fields. Comparison with film-measured relative dose distributions for IMRT fields yields agreement within 3 mm, 5%. This novel dose reconstruction algorithm allows for daily patient-specific dosimetry and verification of patient movement.

Drug-induced pericarditis mimicking Brugada syndrome.

Brugada syndrome (BS) is associated with sudden cardiac death in patients with a structurally normal heart. The ECG pattern of BS has also been described in patients with myocardial abnormalities. Cardiac hypersensitivity and myopericarditis have been reported during long-term treatment with mesalazine. We report the case of a man, treated with mesalazine for Crohn's disease who developed drug-induced pericarditis. The ECG showed a coved ST-segment elevation in the right precordial leads V1-V3, a pattern mimicking BS. The ECG normalized in a few days after mesalazine withdrawal and the follow-up was uneventful. The ECG remained normal. Two ajmaline tests were both negative and ruled out the diagnosis of BS. This observation illustrates that a coved ST-segment elevation in the right precordial leads should not be, systematically, regarded as a marker of a specific syndrome, but may also reflect a common electrical manifestation of abnormalities in the right ventricle or pericardium.

Characterization of scattered radiation in kV CBCT images using Monte Carlo simulations.

Kilovoltage (kV) cone beam computed tomography (CBCT) images suffer from a substantial scatter contribution. In this study, Monte Carlo (MC) simulations are used to evaluate the scattered radiation present in projection images. These predicted scatter distributions are also used as a scatter correction technique. Images were acquired using a kV CBCT bench top system. The EGSnrc MC code was used to model the flat panel imager, the phantoms, and the x-ray source. The x-ray source model was validated using first and second half-value layers (HVL) and profile measurements. The HVLs and the profile were found to agree within 3% and 6%, respectively. MC simulated and measured projection images for a cylindrical water phantom and for an anthropomorphic head phantom agreed within 8% and 10%. A modified version of the DOSXYZnrc MC code was used to score phase space files with identified scattered and primary particles behind the phantoms. The cone angle, the source-to-detector distance, the phantom geometry, and the energy were varied to determine their effect on the scattered radiation distribution. A scatter correction technique was developed in which the MC predicted scatter distribution is subtracted from the projections prior to reconstruction. Preliminary testing of the procedure was done with an anthropomorphic head phantom and a contrast phantom. Contrast and profile measurements were obtained for the scatter corrected and noncorrected images. An improvement of 3% for contrast between solid water and a liver insert and 11% between solid water and a Teflon insert were obtained and a significant reduction in cupping and streaking artifacts was observed.

Electrocardiographic predictors of Brugada type response during Na channel blockade challenge.

AIM: To identify ECG predictors of Brugada type response during Na channel blockade challenge. METHODS: We studied prospectively 103 patients (M = 76, 45 +/- 13 years) in whom ECGs were collected during ajmaline challenge. ECG recordings included the high right precordial leads (-2V(1) and -2V(2)). A positive response was defined by a >0.2 mV J point or ST segment elevation and a down-sloping pattern of the ST segment in at least one right precordial lead. RESULTS: Ajmaline challenge was positive in 48 (47%) of the 103 cases. Baseline J wave elevation was greater in -2V(1) (0.077 +/- 0.078 mV vs. 0.038 +/- 0.046 mV, P = 0.003) and -2V(2) (0.149 +/- 0.103 mV vs. 0.043 +/- 0.088 mV, P < 0.001) in cases with a subsequent positive response. In contrast, ST segment elevation and T wave amplitudes were reduced in V(1), V(2) and V(3). Logistic regression showed that J wave elevation in -2V(2) and decreased T wave amplitude in V(3) at baseline were independent predictors of a positive response. Baseline J wave elevation >0.16 mV in -2V(2) had a specificity of 100%, a sensitivity of 40%, a positive predictive value of 100% and a negative predictive value of 28%. CONCLUSION: J wave elevation >0.16 mV in -2V(2) was the strongest predictor of a Brugada type response to Na channel blockade challenge when Brugada syndrome was suspected on a baseline ECG.