Adherence to the 4S-AF Scheme in the Balkan region: Insights from the BALKAN-AF survey.

BACKGROUND: The 4S-AF scheme includes stroke risk, symptoms, severity of burden, and substrate severity domain. AIM: We aimed to assess the adherence to the 4S-AF scheme in patients classified according to stroke risk in post hoc analysis of the BALKAN-AF dataset. METHODS: A 14-week prospective enrolment of consecutive patients with electrocardiographically documented atrial fibrillation (AF) was performed in seven Balkan countries from 2014 to 2015. RESULTS: Low stroke risk (CHA2DS2-VASc score, 0 in males or 1 in females) was present in 162 (6.0%) patients. 2 099 (77.4%) patients had CHA2DS2-VASc score ≥3 in females or ≥2 in males (high stroke risk), and 613 (22.6%) had CHA2DS2-VASc score <3 in females or <2 in males. Seventy-five (46.3%) patients with low stroke risk and 1555 (74.1%) patients with high stroke risk were prescribed oral anticoagulants (OAC). Two thousand six hundred and seventy-seven (98.6%) had data on European Heart Rhythm Association (EHRA) class. Among 2099 patients with high stroke risk, 703 (33.4%) had EHRA class ≥3. Two hundred and seven (29.4%) patients with EHRA class ≥3 and high stroke risk were offered rhythm control; 620 (55.2%) of individuals with first-diagnosed or paroxysmal AF with high stroke risk were offered rhythm control. Two or more comorbidities occurred in 1927 (91.8%) patients with high stroke risk. CONCLUSIONS: OAC overuse was observed in patients with low stroke risk, whilst OAC underuse was evident in those with high risk of stroke. The percentage of highly symptomatic patients with high risk of stroke who were offered a rhythm control strategy was low.

A Randomized Comparison of Delivered Energy in Cardioversion of Atrial Fibrillation: Biphasic Truncated Exponential Versus Pulsed Biphasic Waveforms.

A few randomized trials have compared impedance-compensated biphasic defibrillators in clinical use. We aim to compare pulsed biphasic (PB) and biphasic truncated exponential (BTE) waveforms in a non-inferiority cardioversion (CVS) study. This was a prospective monocentric randomized clinical trial. Eligible patients admitted for elective CVS of atrial fibrillation (AF) between February 2019 and March 2020 were alternately randomized to treatment with either a PB defibrillator (DEFIGARD TOUCH7, Schiller Médical, Wissembourg, France) or a BTE high-energy (BTE-HE) defibrillator (LIFEPAK15, Physio-Control Inc., Redmond, WA, USA). Fixed-energy protocol (200-200-200 J) was administered. CVS success was accepted if sinus rhythm was restored at 1 min post-shock. The study design considered non-inferiority testing of the primary outcome: cumulative delivered energy (CDE). Seventy-three out of 78 randomized patients received allocated intervention: 38 BTE-HE (52%), 35 PB (48%). Baseline characteristics were well-balanced between groups (p > 0.05). Both waveforms had similar CDE (mean ± standard deviation, 95% confidence interval): BTE-HE (253.9 ± 120.2 J, 214-293 J) vs. PB (226.0 ± 109.8 J, 188-264 J), p = 0.31. Indeed, effective PB shocks delivered significantly lower energies by mean of 25.6 J (95% CI 24-27.1 J, p < 0.001). Success rates were similar (BTE-HE vs. PB): 1 min first-shock (84.2% vs. 82.9%), 1 min CVS (97.4% vs. 94.3%), 2 h CVS (94.7% vs. 94.3%), 24 h CVS (92.1% vs. 94.3%), p > 0.05. Safety analysis did not find CVS hazards, reporting insignificant changes of myocardial-specific biomarkers, transient and rare ST-segment deviations, and no case of harmful tachyarrhythmias and apnea. Cardioversion of AF with fixed-energy protocol 200-200-200 J was highly efficient and safe for both PB and BTE-HE waveforms. These similar performances were achieved despite differences in the waveforms' technical design, associated with significantly lower delivered energy for the effective PB shocks. Clinical Trial Registration: Registration number: NCT04032678, trial register: ClinicalTrials.gov.

Quality indicators in the management of atrial fibrillation: the BALKAN-AF survey.

BACKGROUND: The implementation of quality indicators in the atrial fibrillation (AF) care should be considered to improve quality of management and patient outcome. METHODS: In the post-hoc analysis of the BALKAN-AF dataset, we assessed concordance with quality indicators for AF management. Available domains for AF management [patient assessment (baseline), anticoagulation, rate control strategy, rhythm control strategy and risk factor management] were identified and assessed at baseline visit. RESULTS: Among 132 patients with a CHA2DS2-VASc score of 0 (men) or 1 (women), 75 (56.8%) were prescribed oral anticoagulation (OAC). Of 2539 patients with a CHA2DS2-VASc score ≥ 1 for men and ≥ 2 for women, 1890 (74.4%) were prescribed OAC. Among 1088 patients with permanent AF, 110 (10.1%) individuals were prescribed antiarrhythmic drugs (AADs). Of 1616 patients with structural heart disease, 37 (2.2%) were prescribed class IC AADs. Of 1624 patients with paroxysmal or persistent AF, 59 (3.6%) were offered catheter ablation. Among 2712 AF patients, 2121 (78.2%) had hypertension, 671 (24.7%) were obese, 53 (2.0%) had obstructive sleep apnoea, 110 (4.0%) had alcohol abuse and 340 (12.5%) were smokers. CONCLUSIONS: In the BALKAN-AF cohort, the use of OAC for stroke prevention was poorly associated with patients stroke risk. The use of AADs in patients with permanent AF was low. The prescription of class IC AADs to patients with structural heart disease was infrequent. A large proportion of AF patients had their modifiable risk factors identified.

Symptom management strategies: Rhythm vs rate control in patients with atrial fibrillation in the Balkan region: Data from the BALKAN-AF survey.

BACKGROUND: Symptom-focused management is one of the cornerstones of optimal atrial fibrillation (AF) therapy. OBJECTIVES: To evaluate the use of rhythm control and rate control strategy. Second, to identify predictors of the use of amiodarone in patients with rhythm control and of the use of rhythm control strategy in patients with paroxysmal AF in the Balkans. METHODS: Prospective enrolment of consecutive patients from seven Balkan countries to the BALKAN-AF survey was performed. RESULTS: Of 2712 enrolled patients, 2522 (93.0%) with complete data were included: 1622 (64.3%) patients were assigned to rate control strategy and 900 (35.7%) to rhythm control. Patients with rhythm control were younger, more often hospitalised for AF and with less comorbidities (all P < .05) than those with rate control. Symptom score [European Heart Rhythm Association (EHRA)] was not an independent predictor of a rhythm control strategy [odds ratio (OR) 0.99, 95% confidence interval (CI) 0.90-1.10, P = .945]. The most commonly chosen antiarrhythmic agents were amiodarone (49.7%), followed by propafenone (24.3%). CONCLUSION: More than one-third of patients in the BALKAN-AF survey received a rhythm control strategy, and these patients tended to be younger with less comorbidities than those managed with rate control. EHRA symptom score is not significantly associated with rhythm control strategy. The most commonly used antiarrhythmic agents were amiodarone, followed by propafenone.

Impact of multimorbidity and polypharmacy on the management of patients with atrial fibrillation: insights from the BALKAN-AF survey.

OBJECTIVE: We investigated the impact of multimorbidity and polypharmacy on the management of atrial fibrillation (AF) patients in clinical practice and assessed factors associated with polypharmacy and oral anticoagulation (OAC) use in AF patients with multimorbidity and polypharmacy. METHODS: A 14-week prospective study of consecutive non-valvular AF patients was performed in seven Balkan countries. RESULTS: Of 2712 consecutive patients, 2263 patients (83.4%) had multimorbidity (AF + ≥2 concomitant diseases) and 1505 patients (55.5%) had polypharmacy. 1416 (52.2%) patients had both multimorbidity and polypharmacy. Overall, 1164 (82.2%) patients received OAC, 200 (14.1%) patients received antiplatelet drugs alone and 52 (3.7%) patients had no antithrombotic therapy (AT). Non-emergency centre and paroxysmal AF were significantly associated with OAC non-use in patients with multimorbidity, whilst age ≥80 years and non-emergency centre were identified to be independent predictors of OAC non-use in patients with polypharmacy. CONCLUSIONS: Multimorbidity and polypharmacy were common among AF patients in our study. AT was suboptimal and approximately 18% of multimorbid patients with polypharmacy were not anticoagulated. Pattern of AF and non-emergency centre were associated with OAC non-use in AF patients with multimorbidity, whilst non-emergency centre and age ≥80 years were associated with OAC non-use in AF patients with polypharmacy. Key Message Multimorbidity and polypharmacy are common among patients with AF. Antithrombotic therapy was suboptimal in AF patients with multimorbidity and polypharmacy. Approximately, 18% of multimorbid patients with polypharmacy were not anticoagulated.

Treatment implications of renal disease in patients with atrial fibrillation: The BALKAN-AF survey.

BACKGROUND: Atrial fibrillation (AF) often co-exists with renal function (RF) impairment. We investigated the characteristics and management of AF patients across creatinine clearance strata and potential changes in the use of nonvitamin K oral anticoagulants (NOAC) according to different equations for estimation of RF. METHODS: In this post hoc analysis of the BALKAN-AF survey, patients were classified according to RF (Cockcroft-Gault formula) as: preserved/mildly depressed RF (P-RF) ≥50 mL/min, moderately depressed RF (MD-RF) 30-49 mL/min, and severely depressed RF (SD-RF) <30 mL/min. RESULTS: Of 2712 enrolled patients, 2062 (76.0%) had data on RF. Patients with SD-RF and MD-RF were older, had higher mean value of European Heart Rhythm Association score, stroke and bleeding risk scores, and more comorbidities than patients with P-RF (all P < .05). They received oral anticoagulants (OAC), AF catheter ablation, and electrical cardioversion less often than those with P-RF (all P < .05). Rate control, no OAC, single-antiplatelet therapy (SAPT) alone, and loop diuretics were more prevalent in patients with SD-RF and MD-RF than in subjects with P-RF (all P < .005). An important change in NOAC therapy could appear in <1% of patients (Modification of Diet in Renal Disease formula) and in <1% of patients (Chronic Kidney Disease Epidemiology Collaboration group formula). CONCLUSIONS: Patients with SD-RF and MD-RF were older, more symptomatic, had higher stroke and bleeding risk and more comorbidities than those with P-RF. They were less likely to receive OAC and more likely to use rate control strategy, SAPT alone, and no OAC than subjects with P-RF.

Management of patients with newly-diagnosed atrial fibrillation: Insights from the BALKAN-AF survey.

BACKGROUND: BALKAN-AF evaluated patterns of atrial fibrillation (AF) management in real-world clinical practice in the Balkans. The objectives were: to assess the proportion of patients with first-diagnosed AF in the BALKAN-AF cohort and to compare the management of patients with newly-diagnosed AF and those with previously known AF in clinical practice. METHODS: Consecutive patients from 7 Balkan countries were enrolled prospectively to the snapshot BALKAN-AF survey. RESULTS: Of 2712 enrolled patients, 2677 (98.7%) with complete data were included. 631 (23.6%) patients had newly-diagnosed AF and 2046 (76.4%) patients had known AF. Patients with newly-diagnosed AF were more likely to be hospitalized for AF and to receive single antiplatelet therapy (SAPT) alone and less likely to receive OACs than those with known AF (all p < 0.001). The use of OAC was not significantly associated with the CHA2DS2-VASc (p = 0.624) or HAS-BLED score (p = 0.225) on univariate analysis. Treatment in capital city, hypertension, dilated cardiomyopathy, mitral valve disease, country of residence or rate control strategy were independent predictors of OAC use, whilst non-emergency centre, treatment by cardiologist, paroxysmal AF, palpitations, symptoms attributable to AF (as judged by physician), mean heart rate and AF as the main reason for hospitalization were independent predictors of rhythm control strategy use. CONCLUSIONS: In BALKAN-AF survey, patients with newly-diagnosed AF were more often hospitalized, less often received OAC and were more likely to receive SAPT alone. The use of OAC for stroke prevention has not been driven by the individual patient stroke risk.

Adherence to the ABC (Atrial fibrillation Better Care) pathway in the Balkan region: the BALKAN-AF survey.

INTRODUCTION: The Atrial fibrillation Better Care (ABC) pathway provides a useful way of simplifying decision­making considerations in a holistic approach to atrial fibrillation management. OBJECTIVES: To evaluate adherence to the ABC pathway and to determine major gaps in adherence in patients in the BALKAN­AF survey. PATIENTS AND METHODS: In this ancillary analysis, patients from the BALKAN­AF survey were divided into the following groups: A (avoid stroke) + B (better symptom control) + C (cardiovascular and comorbidity risk management)-adherent and -nonadherent management. RESULTS: Among 2712 enrolled patients, 1013 (43.8%) patients with mean (SD) age of 68.8 (10.2) years and mean CHA2DS2­VASc score of 3.4 (1.8) had A+B+C-adherent management and 1299 (56.2%) had A+B+C-nonadherent management. Independent predictors of increased A+B+C-adherent management were: capital city (odds ratio [OR], 1.23; 95% CI, 1.03-1.46; P = 0.02), treatment by cardiologist (OR, 1.34; 95% CI, 1.08-1.66; P = 0.01), hypertension (OR, 2.2; 95% CI, 1.74-2.77; P <0.001), diabetes mellitus (OR, 1.28; 95% CI, 1.05-1.57; P = 0.01), and multimorbidity (the presence of 2 or more long­ term conditions) (OR, 1.85; 95% CI, 1.43-2.38; P <0.001). Independent predictors of decreased A+B+C-adherent management were: age 80 years or older (OR, 0.61; 95% CI, 0.48-0.76; P <0.001) and history of bleeding (OR, 0.5; 95% CI, 0.33-0.75; P = 0.001). CONCLUSIONS: Physicians' adherence to integrated AF management based on the ABC pathway was suboptimal. Addressing the identified clinical and system­related factors associated with A+B+C-nonadherent management using targeted approaches is needed to optimize treatment of patients with AF in the Balkan region.

Stroke prevention in elderly patients with non-valvular atrial fibrillation in the BALKAN-AF survey.

BACKGROUND: Atrial fibrillation (AF) is common amongst the elderly, but this group tends to be suboptimally treated. Limited data are available on the stroke prevention strategies in the elderly, especially in the Balkan region. AIM: We investigated the use of oral anticoagulant therapy (OAC) amongst elderly AF patients in clinical practice in the Balkan region. METHOD: A 12-week prospective snapshot survey (2014-2015) of consecutive non-valvular AF patients was conducted in Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Montenegro, Romania and Serbia. Data were collected via an electronic case report form. RESULTS: Of 2671 patients, 418 (15.6%) were ≥80 years old. Overall, OAC was used in 1965 patients (73.6%). Compared with younger patients, the elderly (age ≥ 80) had a higher mean CHA2 DS2 -VASc score (3.22 ± 1.71 vs 4.89 ± 1.35, P < .001) and more often a HAS-BLED score of ≥3 (n = 198 [47.0%] vs n = 625 [27.3%], P < .001), but were less likely to receive OAC (n = 269 [64.4%] vs n = 1696 [75.3%], odds ratio [OR] 0.91; 95%CI 0.86-0.97, P = .003). There was no significant association between OAC use and mean CHA2 DS2 -VASc (OR 0.86; 95%CI 0.75-1.00, P = .053) or HAS-BLED score (OR 1.21; 95%CI 0.81-1.81, P = .349) in the elderly. CONCLUSION: In the BALKAN-AF Survey, elderly AF patients were less likely to receive the guideline-adherent treatment despite their less favourable risk profile. Since OAC nonuse among the elderly was not associated with increased HAS-BLED score, factors other than patients' risk profile could influence the implementation of guideline-adherent treatment for thromboprophylaxis in the elderly AF patients.

Cardioversion of Atrial Fibrillation and Flutter: Comparative Study of Pulsed vs. Low Energy Biphasic Truncated Exponential Waveforms.

BACKGROUND: Despite the widespread use of biphasic waveforms for cardioversion and defibrillation, the efficacy and safety of shocks has only been compared in a few studies. METHODS: This retrospective study aims at comparing the efficacy and safety of biphasic truncated exponential (BTE) pulsed energy (PE) waveform with a BTE low energy (LE) waveform for cardioversion of atrial fibrillation (AF) and atrial flutter (AFL). The treatment energies were following an escalating protocol for PE waveform (120-200-200J in AF and 30-120-200J in AFL) and LE waveform (100-200-200J in AF and 30-100-200J in AFL). The protocol was stopped at successful cardioversion (sinus rhythm at 1 minute post-shock), otherwise after the 3rd shock. If the 3rd BTE shock failed, a monophasic shock of 360J was delivered. RESULTS: From May 2008 to November 2017, 193 patients (153 PE, 40 LE) were included in the study. Both groups significantly differed in a few characteristics, including chest circumference (p<0.05). After adjustment, the success rate was not significantly different for the two waveforms (94.5% PE vs 92.5% LE, Odds Ratio [95% Confidence Interval] = 0.25 [0.03-2.2]).There was no difference in safety: post-shock changes in Hsc-TnI levels were similar (p=0.25). The efficient cumulative energy was particularly related with BSA (ß = 131.5, p=0.05), AF/AFL duration (ß = 0.24, p=0.01) and gender (ß = 61.8, p=0.05). CONCLUSIONS: The major clinical implications of this study concern the high success rate of cardioversion with both biphasic pulses and no superiority of LE over PE waveform with an excellent safety profile without post-shock myocardial injuries.

Unrecognised cardiovascular disease in type 2 diabetes: is it time to act earlier?

Cardiovascular disease (CVD) is the most significant prognostic factor in individuals with type 2 diabetes (T2D). However, a significant number of individuals may develop CVD that does not present with the classic angina-related or heart failure symptoms. In these cases, CVD may seem to be 'silent' or 'asymptomatic', but may be more accurately characterised as unrecognised diabetic cardiac impairment. An initial step to raise awareness of unrecognised CVD in individuals with T2D would be to reach a consensus regarding the terminology used to describe this phenomenon. By standardising the terminologies, and agreeing on the implementation of an efficient screening program, it is anticipated that patients will receive an earlier diagnosis and appropriate and timely treatment. Given the availability of anti-diabetic medications that have been shown to concomitantly reduce CV risk and mortality, it is imperative to improve early identification and initiate treatment as soon as possible in order to enable as many patients with T2D as possible to benefit.

Editor's Choice - Acute Cardiovascular Care Association Position Paper on Intensive Cardiovascular Care Units: An update on their definition, structure, organisation and function.

Acute cardiovascular care has progressed considerably since the last position paper was published 10 years ago. It is now a well-defined, complex field with demanding multidisciplinary teamworking. The Acute Cardiovascular Care Association has provided this update of the 2005 position paper on acute cardiovascular care organisation, using a multinational working group. The patient population has changed, and intensive cardiovascular care units now manage a large range of conditions from those simply requiring specialised monitoring, to critical cardiovascular diseases with associated multi-organ failure. To describe better intensive cardiovascular care units case mix, acuity of care has been divided into three levels, and then defining intensive cardiovascular care unit functional organisation. For each level of intensive cardiovascular care unit, this document presents the aims of the units, the recommended management structure, the optimal number of staff, the need for specially trained cardiologists and cardiovascular nurses, the desired equipment and architecture, and the interaction with other departments in the hospital and other intensive cardiovascular care units in the region/area. This update emphasises cardiologist training, referring to the recently updated Acute Cardiovascular Care Association core curriculum on acute cardiovascular care. The training of nurses in acute cardiovascular care is additionally addressed. Intensive cardiovascular care unit expertise is not limited to within the unit's geographical boundaries, extending to different specialties and subspecialties of cardiology and other specialties in order to optimally manage the wide scope of acute cardiovascular conditions in frequently highly complex patients. This position paper therefore addresses the need for the inclusion of acute cardiac care and intensive cardiovascular care units within a hospital network, linking university medical centres, large community hospitals, and smaller hospitals with more limited capabilities.

The Patterns of Non-vitamin K Antagonist Oral Anticoagulants (NOACs) Use in Patients with Atrial Fibrillation in Seven Balkan Countries: a Report from the BALKAN-AF Survey.

INTRODUCTION: Data on management of atrial fibrillation (AF) in the Balkan Region are scarce. To capture the patterns in AF management in contemporary clinical practice in the Balkan countries a prospective survey was conducted between December 2014 and February 2015, and we report results pertinent to the use of non-vitamin K antagonist oral anticoagulants (NOACs). METHODS: A 14-week prospective, multicenter survey of consecutive AF patients seen by cardiologists or internal medicine specialists was conducted in Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Montenegro, Romania, and Serbia (a total of about 50 million inhabitants). RESULTS: Of 2712 enrolled patients, 2663 (98.2%) had complete data relevant to oral anticoagulant (OAC) use (mean age 69.1 ± 10.9 years, female 44.6%). Overall, OAC was used in 1960 patients (73.6%) of whom 338 (17.2%) received NOACs. Malignancy [odds ratio (OR), 95% confidence interval (CI) 2.06, 1.20-3.56], rhythm control (OR 1.64, 1.25-2.16), and treatment by cardiologists were independent predictors of NOAC use (OR 2.32, 1.51-3.54) [all p < 0.01)], whilst heart failure and valvular disease were negatively associated with NOAC use (both p < 0.01). Individual stroke and bleeding risk were not significantly associated with NOAC use on multivariate analysis. CONCLUSIONS: NOACs are increasingly used in AF patients in the Balkan Region, but NOAC use is predominantly guided by factors other than evidence-based decision-making (e.g., drug availability on the market or reimbursement policy). Efforts are needed to establish an evidence-based approach to OAC selection and to facilitate the optimal use of OAC, thus improving the outcomes in AF patients in this large region.

Stroke prevention in atrial fibrillation and 'real world' adherence to guidelines in the Balkan Region: The BALKAN-AF Survey.

Data on the management of atrial fibrillation (AF) in the Balkan Region are limited. The Serbian AF Association (SAFA) prospectively investigated contemporary 'real-world' AF management in clinical practice in Albania, Bosnia&Herzegovina, Bulgaria, Croatia, Montenegro, Romania and Serbia through a 14-week (December 2014-February 2015) prospective, multicentre survey of consecutive AF patients. We report the results pertinent to stroke prevention strategies. Of 2712 enrolled patients, 2663 (98.2%) with complete data were included in this analysis (mean age 69.1 ± 10.9 years, female 44.6%). Overall, 1960 patients (73.6%) received oral anticoagulants (OAC) and 762 (28.6%) received antiplatelet drugs. Of patients given OAC, 17.2% received non-vitamin K antagonist oral anticoagulants (NOACs). CHA2DS2-VASc score was not significantly associated with OAC use. Of the 'truly low-risk' patients (CHA2DS2-VASc = 0 [males], or 1 [females]) 56.5% received OAC. Time in Therapeutic Range (TTR) was available in only 18.7% of patients (mean TTR: 49.5% ± 22.3%). Age ≥ 80 years, prior myocardial infarction and paroxysmal AF were independent predictors of OAC non-use. Our survey shows a relatively high overall use of OAC in AF patients, but with low quality of vitamin K antagonist therapy and insufficient adherence to AF guidelines. Additional efforts are needed to improve AF-related thromboprophylaxis in clinical practice in the Balkan Region.

Dataset of manually measured QT intervals in the electrocardiogram.

BACKGROUND: The QT interval and the QT dispersion are currently a subject of considerable interest. Cardiac repolarization delay is known to favor the development of arrhythmias. The QT dispersion, defined as the difference between the longest and the shortest QT intervals or as the standard deviation of the QT duration in the 12-lead ECG is assumed to be reliable predictor of cardiovascular mortality. The seventh annual PhysioNet/Computers in Cardiology Challenge, 2006 addresses a question of high clinical interest: Can the QT interval be measured by fully automated methods with accuracy acceptable for clinical evaluations? METHOD: The PTB Diagnostic ECG Database was given to 4 cardiologists and 1 biomedical engineer for manual marking of QRS onsets and T-wave ends in 458 recordings. Each recording consisted of one selected beat in lead II, chosen visually to have minimum baseline shift, noise, and artifact.In cases where no T wave could be observed or its amplitude was very small, the referees were instructed to mark a 'group-T-wave end' taking into consideration leads with better manifested T wave.A modified Delphi approach was used, which included up to three rounds of measurements to obtain results closer to the median. RESULTS: A total amount of 2*5*548 Q-onsets and T-wave ends were manually marked during round 1. To obtain closer to the median results, 8.58 % of Q-onsets and 3.21 % of the T-wave ends had to be reviewed during round 2, and 1.50 % Q-onsets and 1.17 % T-wave ends in round 3. The mean and standard deviation of the differences between the values of the referees and the median after round 3 were 2.43 +/- 0.96 ms for the Q-onset, and 7.43 +/- 3.44 ms for the T-wave end. CONCLUSION: A fully accessible, on the Internet, dataset of manually measured Q-onsets and T-wave ends was created and presented in additional file: 1 (Table 4) with this article. Thus, an available standard can be used for the development of automated methods for the detection of Q-onsets, T-wave ends and for QT interval measurements.