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Aims Within the TeleCheck-AF project, numerous centres in Europe used on-demand photoplethysmography (PPG) technology to remotely assess heart rate and rhythm in conjunction with teleconsultations. Based on the TeleCheck-AF investigator experiences, we aimed to develop an educational structured stepwise practical guide on how to interpret PPG signals and to introduce typical clinical scenarios how on-demand PPG was used. Methods and results During an online conference, the structured stepwise practical guide on how to interpret PPG signals was discussed and further refined during an internal review process. We provide the number of respective PPG recordings (FibriCheck®) and number of patients managed within a clinical scenario during the TeleCheck-AF project. To interpret PPG recordings, we introduce a structured stepwise practical guide and provide representative PPG recordings. In the TeleCheck-AF project, 2522 subjects collected 90 616 recordings in total. The majority of these recordings were classified by the PPG algorithm as sinus rhythm (57.6%), followed by AF (23.6%). In 9.7% of recordings, the quality was too low to interpret. The most frequent clinical scenarios where PPG technology was used in the TeleCheck-AF project was a follow-up after AF ablation (1110 patients) followed by heart rate and rhythm assessment around (tele)consultation (966 patients). Conclusion We introduce a newly developed structured stepwise practical guide on PPG signal interpretation developed based on presented experiences from TeleCheck-AF. The present clinical scenarios for the use of on-demand PPG technology derived from the TeleCheck-AF project will help to implement PPG technology in the management of AF patients.

Funding Acknowledgements Type of funding sources: None. OnBehalf TeleCheck-AF Investigators Aims TeleCheck-AF is a multicentre international project initiated to maintain care delivery for patients with atrial fibrillation (AF) during COVID-19 through teleconsultations supported by an on-demand photoplethysmography-based heart rate and rhythm monitoring app (FibriCheck®). We describe the characteristics and experiences from recruited patients. Methods Self-reported patient characteristics were obtained from the app. A survey exploring patient experiences completed by 826 patients. Results Within 28 weeks, 1930 AF patients were recruited by 38 centers in 14 countries, mainly for remote AF control (31% of patients) and AF ablation follow-up (42%). One-third of patients was in the age range 60-69 years. The most common comorbidity was hypertension (42% of all patients). More than 70% of patients were treated with oral anticoagulation. In total 59.858 heart rate and rhythm measurements were recorded. During the one-week FibriCheck® use, patient adherence was high. Patients performed between 2 and 5 recordings a day and the median number of measurements per patient was 21 [15-29]. The highest average number of measurements per patient was seen in patients older than 80years of age. Patients agreed that the FibriCheck® app was easy to use (94%) and easy to install (89%). The app gave patients a safe feeling (74%) due to being in constant heart rate and rhythm control. More than half of the patients (58%) agreed or strongly agreed that they would like to use the FibriCheck® app in the future. They also found the automated reminders useful (64%). Conclusions In the TeleCheck-AF project, mHealth adherence was high, particularly in older patients ≥80 years. The app FibriCheck® is easy to use for 7 days before a scheduled teleconsultation. Patients think that remote rate and rhythm monitoring around teleconsultation by the TeleCheck-AF approach may be an alternative to traditional face-to-face consultations in the future. Abstract Figure.

Aims TeleCheck-AF is a multicentre international project initiated to maintain care delivery for patients with atrial fibrillation (AF) during COVID-19 through teleconsultations supported by an on-demand photoplethysmography-based heart rate and rhythm monitoring app (FibriCheck®). We describe the characteristics, inclusion rates, and experiences from participating centres according the TeleCheck-AF infrastructure as well as characteristics and experiences from recruited patients. Methods and results Three surveys exploring centre characteristics (n = 25), centre experiences (n = 23), and patient experiences (n = 826) were completed. Self-reported patient characteristics were obtained from the app. Most centres were academic (64%) and specialized public cardiology/district hospitals (36%). Majority of the centres had AF outpatient clinics (64%) and only 36% had AF ablation clinics. The time required to start patient inclusion and total number of included patients in the project was comparable for centres experienced (56%) or inexperienced in mHealth use. Within 28 weeks, 1930 AF patients were recruited, mainly for remote AF control (31% of patients) and AF ablation follow-up (42%). Average inclusion rate was highest during the lockdown restrictions and reached a steady state at a lower level after easing the restrictions (188 vs. 52 weekly recruited patients). Majority (>80%) of the centres reported no problems during the implementation of the TeleCheck-AF approach. Recruited patients [median age 64 (55–71), 62% male] agreed that the FibriCheck® app was easy to use (94%). Conclusion Despite different health care settings and mobile health experiences, the TeleCheck-AF approach could be set up within an extremely short time and easily used in different European centres during COVID-19.

The aim of this European Heart Rhythm Association (EHRA) survey was to assess the utilization of same-day discharge (SDD) in electrophysiology (EP). An online-based questionnaire was shared with the EHRA community between 12 and 30 June 2020 and recorded institutional information, complication assessment, recent experiences, and opinions regarding possible advantages or concerns with SDD. In total, 218 responses from 49 countries provided information on current SDD management. Overall, SDD was implemented in 77.5%, whereas this proportion was significantly higher in tertiary and high-volume centres (83.8% and 85.3%, both P 75% of respondents already implement SDD following EP interventions with a large heterogeneity with regard to specific procedures. Further research is needed to confirm or disprove existing and expected benefits and obstacles.

Background Epicardial ganglionated plexuses (GP) have an important role in the pathogenesis of atrial fibrillation (AF). The relationship between anatomical, histological and functional effects of GP is not well known. We previously described atrioventricular (AV) dissociating GP (AVD-GP) locations. In this study, we hypothesised that ectopy triggering GP (ET-GP) are upstream triggers of atrial ectopy/AF and have different anatomical distribution to AVD-GP. Objectives We mapped and characterised ET-GP to understand their neural mechanism in AF and anatomical distribution in the left atrium (LA). Methods 26 patients with paroxysmal AF were recruited. All were paced in the LA with an ablation catheter. High frequency stimulation (HFS) was synchronised to each paced stimulus for delivery within the local atrial refractory period. HFS responses were tagged onto CARTO™ 3D LA geometry. All geometries were transformed onto one reference LA shell. A probability distribution atlas of ET-GP was created. This identified high/low ET-GP probability regions. Results 2302 sites were tested with HFS, identifying 579 (25%) ET-GP. 464 ET-GP were characterised, where 74 (16%) triggered ≥30s AF/AT. Median 97 (IQR 55) sites were tested, identifying 19 (20%) ET-GP per patient. >30% of ET-GP were in the roof, mid-anterior wall, around all PV ostia except in the right inferior PV (RIPV) in the posterior wall. Conclusion ET-GP can be identified by endocardial stimulation and their anatomical distribution, in contrast to AVD-GP, would be more likely to be affected by wide antral circumferential ablation. This may contribute to AF ablation outcomes., Highlights • ET-GP can be stimulated endocardially using high frequency stimulation within the local atrial refractory period. • ET-GP stimulation displays a wide range of responses from single ectopy to sustained AF and occasionally AV block. • ET-GP have distinct anatomical regions in patients with AF, and their distribution contrasts that of AV dissociating GP. • Most ET-GP are in the roof/PV ostia and inadvertently ablated during PVI. This may contribute to AF ablation success.

An 85-year-old male was admitted to our center with a non-ST elevation myocardial infarction. The patient had a dual-chamber pacemaker in situ with an atrial and His lead. A transient increase in His threshold and loss of nonselective capture occurred at the presentation of right coronary artery infarction, peaking during rotational atherectomy therapy causing loss of capture and complete atrioventricular block. A follow-up interrogation, 2 weeks postrevascularization, showed a return to a normal nonselective capture morphology and threshold measurements. Physicians should be aware of this complication in patients with His leads, particularly those with a history of coronary artery disease.

OBJECTIVE We tested whether ablation methodology and study design can explain the varying outcomes in terms of atrial fibrillation (AF)-free survival at 1 year. BACKGROUND There have been numerous paroxysmal AF ablation trials, which are heterogeneous in their use of different ablation techniques and study design. A useful approach to understanding how these factors influence outcome is to dismantle the trials into individual arms and reconstitute them as a large meta-regression. METHODS Data were collected from 66 studies (6941 patients). With freedom from AF as the dependent variable, we performed meta-regression using the individual study arm as the unit. RESULTS Success rates did not change regardless of the technique used to produce pulmonary vein isolation (PVI). Neither was adjunctive lesion sets associated with any improvement in outcome. Studies that included more males and fewer hypertensive patients were found more likely to report better outcomes. The electrocardiography method selected to assess outcome also plays an important role. Outcomes were worse in studies that used regular telemonitoring (by 23%; P

Aims In patients with heart failure and a pathologically prolonged PR interval, left ventricular (LV) filling can be improved by shortening atrioventricular delay using His-bundle pacing. His-bundle pacing delivers physiological ventricular activation and has been shown to improve acute haemodynamic function in this group of patients. In the HOPE-HF (His Optimized Pacing Evaluated for Heart Failure) trial, we are investigating whether these acute haemodynamic improvements translate into improvements in exercise capacity and heart failure symptoms. Methods and results This multicentre, double-blind, randomized, crossover study aims to randomize 160 patients with PR prolongation (≥200 ms), LV impairment (EF ≤ 40%), and either narrow QRS (≤140 ms) or right bundle branch block. All patients receive a cardiac device with leads positioned in the right atrium and the His bundle. Eligible patients also receive a defibrillator lead. Those not eligible for implantable cardioverter defibrillator have a backup pacing lead positioned in an LV branch of the coronary sinus. Patients are allocated in random order to 6 months of (i) haemodynamically optimized dual chamber His-bundle pacing and (ii) backup pacing only, using the non-His ventricular lead. The primary endpoint is change in exercise capacity assessed by peak oxygen uptake. Secondary endpoints include change in ejection fraction, quality of life scores, B-type natriuretic peptide, daily patient activity levels, and safety and feasibility assessments of His-bundle pacing. Conclusions Hope-HF aims to determine whether correcting PR prolongation in patients with heart failure and narrow QRS or right bundle branch block using haemodynamically optimized dual chamber His-bundle pacing improves exercise capacity and symptoms. We aim to complete recruitment by the end of 2018 and report in 2020.

The heart is served by intrinsic, efficient and coordinated electrical activation provided by its specialised conduction system. The conduction system can be damaged, requiring the provision of pacing to maintain an adequate cardiac output. Causes of cardiac conduction disease are most commonly idiopathic or degenerative relating to calcium deposition. Pacing is not uncommonly indicated after cardiac surgery, particularly following procedures on the aortic valve especially in the presence of underlying conduction disease. The disturbance and damage caused to the conduction system may be short lived and resolve whilst back-up pacing support is provided by a temporary pacing system or more permanent damage may result requiring a permanent pacing solution. Managing a temporary pacing system and determining if and when to convert to a permanent pacing approach can at times be difficult. This chapter provides an overview of standard indications for pacemakers and implantable defibrillators as well as clarifies basic principles of pacing including commonly used terms such as threshold and sensitivity. It explores new developments in the sphere of cardiac pacing such as pacemakers in an MRI field as well as emerging technologies namely leadless and His bundle pacing. It includes a practical section on troubleshooting of temporary epicardial systems and provides insight into cases where cardiac surgeons may be called upon to assist cardiology colleagues, namely, surgical lead implantation or lead extraction.

AimsAblation of persistent atrial fibrillation (PsAF) has been performed by many techniques with varying success rates. This may be due to ablation techniques, patient demographics, comorbidities, and trial design. We conducted a meta-regression of studies of PsAF ablation to elucidate the factors affecting atrial fibrillation (AF) recurrence.Methods and results Databases were searched for prospective studies of PsAF ablation. A meta-regression was performed. Fifty-eight studies (6767 patients) were included. Complex fractionated atrial electrogram (CFAE) ablation reduced freedom from AF by 8.9% [95% confidence interval (CI) −15 to −2.3, P = 0.009). Left atrial appendage [LAA isolation (three study arms)] increased freedom from AF by 39.5% (95% CI 9.1–78.4, P = 0.008). Posterior wall isolation (PWI) (eight study arms) increased freedom from AF by 19.4% (95% CI 3.3–38.1, P = 0.017). Linear ablation or ganglionated plexi ablation resulted in no significant effect on freedom from AF. More extensive ablation increased intraprocedural AF termination; however, intraprocedural AF termination was not associated with improved outcomes. Increased left atrial diameter was associated with a reduction in freedom from AF by 4% (95% CI −6.8% to −1.1%, P = 0.007) for every 1 mm increase in diameter.Conclusion Linear ablation, PWI, and CFAE ablation improves intraprocedural AF termination, but such termination does not predict better long-term outcomes. Study arms including PWI or LAA isolation in the lesion set were associated with improved outcomes in terms of freedom from AF; however, further randomized trials are required before these can be routinely recommended. Left atrial size is the most important marker of AF chronicity influencing outcomes.

IntroductionElectrical coupling index (ECI) and contact force (CF) have been developed to aid lesion formation during catheter ablation. ECI measures tissue impedance and capacitance whilst CF measures direct contact. The aim was to determine whether the presence of catheter / tissue interaction information, such as ECI and CF, reduce time to achieve bidirectional cavotricuspid isthmus block during atrial flutter (AFL) ablation.MethodsPatients with paroxysmal or persistent AFL were randomised to CF visible (range 5-40g), CF not visible, ECI visible (change of 12%) or ECI not visible. Follow-up occurred at 3 and 6 months and included a 7 day ECG recording. The primary endpoint was time to bidirectional cavotricuspid isthmus block.Results114 patients were randomised, 16 were excluded. Time to bidirectional block was significantly shorter when ECI was visible (median 30.0 mins (IQR 31) to median 10.5mins (IQR 12) p 0.023) versus ECI not visible. There was a trend towards a shorter time to bidirectional block when CF was visible. Higher force was applied when CF was visible (median 9.03g (IQR 7.4) vs. 11.3g (5.5) p 0.017). There was no difference in the acute recurrence of conduction between groups. The complication rate was 2%, AFL recurrence was 1.1% and at 6 month follow-up, 12% had atrial fibrillation.ConclusionThe use of tissue contact information during AFL ablation was associated with reduced time taken to achieve bidirectional block when ECI was visible. Contact force data improved contact when visible with a trend towards a reduction in the procedural endpoint. ClinicalTrials.gov trial identifier: NCT02490033.

Objectives The purpose of this study was to investigate whether heart failure patients with narrow QRS duration (or right bundle branch block) but with long PR interval gain acute hemodynamic benefit from atrioventricular (AV) optimization. We tested this with biventricular pacing and (to deliver pure AV shortening) direct His bundle pacing. Background Benefits of pacing for heart failure have previously been indicated by acute hemodynamic studies and verified in outcome studies. A new target for pacing in heart failure may be PR interval prolongation, which is associated with 58% higher mortality regardless of QRS duration. Methods We enrolled 16 consecutive patients with systolic heart failure, PR interval prolongation (mean, 254 ± 62 ms) and narrow QRS duration (n = 13; mean QRS duration: 119 ± 17 ms) or right bundle branch block (n = 3; mean, QRS duration: 156 ± 18 ms). We successfully delivered temporary direct His bundle pacing in 14 patients and temporary biventricular pacing in 14 participants. We performed AV optimization using invasive systolic blood pressure obtaining parabolic responses (mean R 2 : 0.90 for His, and 0.85 for biventricular pacing). Results The mean increment in systolic BP compared with intrinsic ventricular conduction was 4.1 mm Hg (95% confidence interval [CI]: +1.9 to +6.2 mm Hg for His and 4.3 mm Hg [95% CI: +2.0 to +6.5 mm Hg] for biventricular pacing. QRS duration lengthened with biventricular pacing (change = +22 ms [95% CI: +18 to +25 ms]) but not with His pacing (change = +0.5 ms [95% CI: −2.6 to +3.6 ms). Conclusions AV-optimized pacing improves acute hemodynamic function in patients with heart failure and long PR interval without left bundle branch block. That it can be achieved by single-site His pacing shows that its mechanism is AV shortening. The improvement is ∼60% of the effect size previously reported for biventricular pacing in left bundle branch block. Randomized, blinded trials are warranted to test for long-term beneficial effects.

Objectives This study examined the time course of clinical events in cardiac resynchronization therapy (CRT) trials. Background Recent randomized controlled trial results suggest that in heart failure with narrow QRS, biventricular pacing (CRT) may increase mortality. The authors proposed implant complications as the cause, rather than a progressive adverse physiological effect. Methods The study identified all trials comparing CRT with no CRT, which reported Kaplan-Meier curves in groups defined by QRS: narrow, non–left bundle branch block (LBBB) broad, and LBBB broad. For each trial, the change in life span every 3 months up to 3.5 years (the longest time for which data are available) was calculated and a power law was fitted, that is, ∝ timen. Results Four trials (MADIT-CRT [Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy], RAFT [Resynchronization-Defibrillation for Ambulatory Heart Failure Trial], REVERSE [REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction], and EchoCRT [Echocardiography Guided Cardiac Resynchronization Therapy]), totaling 4,717 patients, reported curves for mortality or heart failure–related hospitalization, or for mortality. In patients with LBBB broad QRS (within MADIT-CRT), life span gain increased in proportion to time1.94. In contrast, in patients with non-LBBB broad QRS (within MADIT-CRT) and patients with narrow QRS (EchoCRT), life span was lost in proportion to time1.92 and time,1.96 respectively. Hospitalization-free survival showed similar patterns. Conclusions The nonlinear growth of life span gained when a CRT device is implanted in patients with LBBB broad QRS is unfortunately mirrored by a similarly progressive loss in life span in narrow QRS heart failure. This suggests the culprit is a progressive physiological effect of pacing rather than implant complications. If these data are not sufficient, a randomized controlled trial of deactivating CRT in patients with narrow QRS may now be needed, with a primary endpoint of increasing survival.

An old bunch of young cardiologists dating back to 1948! The British Junior Cardiologists' Association (BJCA) represents over 1000 aspiring cardiologists and cardiologists in training in the UK. We believe the BJCA can make claim to be the oldest young cardiologists' group in Europe, emerging from a group known as the ‘Junior Cardiac Club’ founded in 1948. The first chair was the distinguished cardiologist Dr Walter Somerville who started the society when he was a cardiologist in training at the Hammersmith Hospital in London working alongside Paul Wood performing some of the first cardiac catheterization procedures in the UK at the time.1 ![Graphic][1] ![Graphic][2] Dr Somerville went on to become President of the British Cardiac Society and Editor of the journal Heart. In 2000 the Junior Cardiac Club merged with other British regional young cardiologist' groups to become the BJCA and in 2007 was one of the founding members of the now thriving and ever expanding ESC Cardiologists' of Tomorrow community. As does the ESC CoT, the BJCA has a tradition of supporting young cardiologists become the leaders in cardiovascular medicine of tomorrow with many of its alumni shaping the future of cardiology. With the support of the British Cardiovascular Society and its affiliated groups, the BJCA works closely to represent the interests of cardiologists' in training with representation on committees which oversee cardiology training and it closely interacts with trainee groups from other medical specialties. With the proliferation of doctor in training groups across the UK … [1]: /embed/inline-graphic-1.gif [2]: /embed/inline-graphic-2.gif

Background Localizing the origin of outflow tract ventricular tachycardias (OTVT) is hindered by lack of accuracy of electrocardiographic (ECG) algorithms and infrequent spontaneous premature ventricular complexes (PVCs) during electrophysiological studies. Objectives To prospectively assess the performance of noninvasive electrocardiographic mapping (ECM) in the pre-/periprocedural localization of OTVT origin to guide ablation and to compare the accuracy of ECM with that of published ECG algorithms. Methods Patients with symptomatic OTVT/PVCs undergoing clinically indicated ablation were recruited. The OTVT/PVC origin was mapped preprocedurally by using ECM, and 3 published ECG algorithms were applied to the 12-lead ECG by 3 blinded electrophysiologists. Ablation was guided by using ECM. The OTVT/PVC origin was defined as the site where ablation caused arrhythmia suppression. Acute success was defined as abolition of ectopy after ablation. Medium-term success was defined as the abolition of symptoms and reduction of PVC to less than 1000 per day documented on Holter monitoring within 6 months. Results In 24 patients (mean age 50 ± 18 years) recruited ECM successfully identified OTVT/PVC origin in 23/24 (96%) (right ventricular outflow tract, 18; left ventricular outflow tract, 6), sublocalizing correctly in 100% of this cohort. Acute ablation success was achieved in 100% of the cases with medium-term success in 22 of 24 patients. PVC burden reduced from 21,837 ± 23,241 to 1143 ± 4039 (P < .0001). ECG algorithms identified the correct chamber of origin in 50%–88% of the patients and sublocalized within the right ventricular outflow tract (septum vs free-wall) in 37%–58%. Conclusions ECM can accurately identify OTVT/PVC origin in the left and the right ventricle pre- and periprocedurally to guide catheter ablation with an accuracy superior to that of published ECG algorithms.

OBJECTIVE Optimization of cardiac resynchronization therapy using non-invasive haemodynamic parameters produces reliable optima when performed at high atrial paced heart rates. Here we investigate whether this is a result of increased heart rate or atrial pacing itself. APPROACH Forty-three patients with cardiac resynchronization therapy underwent haemodynamic optimization of atrioventricular (AV) delay using non-invasive beat-to-beat systolic blood pressure in three states: rest (atrial-sensing, 66 ± 11 bpm), slow atrial pacing (73 ± 12 bpm), and fast atrial pacing (94 ± 10 bpm). A 20-patient subset underwent a fourth optimization, during exercise (80 ± 11 bpm). MAIN RESULTS Intraclass correlation coefficient (ICC, quantifying information content mean ±SE) was 0.20 ± 0.02 for resting sensed optimization, 0.45 ± 0.03 for slow atrial pacing (p

Background— The activation pattern of localized reentry (LR) in atrial tachycardia remains incompletely understood. We used the ultra–high density Rhythmia mapping system to study activation patterns in LR. Methods and Results— LR was suggested by small rotatory activations (carousels) containing the full spectrum of the color-coded map. Twenty-three left-sided atrial tachycardias were mapped in 15 patients (age: 64±11 years). 16 253±9192 points were displayed per map, collected over 26±14 minutes. A total of 50 carousels were identified (median 2; quartiles 1–3 per map), although this represented LR in only n=7 out of 50 (14%): here, rotation occurred around a small area of scar ( Conclusions— The activation pattern of LR is of small stable rotational activations (carousels), and this drove 30% (7/23) of our postablation atrial tachycardias. However, this appearance is most often pseudo-reentrant and must be differentiated by interpretation of electrograms in the candidate circuit and activation in the wider surrounding region.

Biventricular pacing has revolutionised the treatment of heart failure in patients with sinus rhythm and left bundle branch block; however, left ventricular-lead placement is not always technically possible. Furthermore, biventricular pacing does not fully normalise ventricular activation and, therefore, the ventricular resynchronisation is imperfect. Right ventricular pacing for bradycardia may cause or worsen heart failure in some patients by causing dyssynchronous ventricular activation. His bundle pacing activates the ventricles via the native His-Purkinje system, resulting in true physiological pacing, and, therefore, is a promising alternate site for pacing in bradycardia and traditional CRT indications in cases where it can overcome left bundle branch block. Furthermore, it may open up new indications for pacing therapy in heart failure, such as targeting patients with PR prolongation, but a narrow QRS duration. In this article we explore the physiology, technology and potential roles of His bundle pacing in the prevention and treatment of heart failure.

Background Biventricular pacing ( CRT ) shows clear benefits in heart failure with wide QRS , but results in narrow QRS have appeared conflicting. We tested the hypothesis that study design might have influenced findings. Method and Results We identified all reports of CRT ‐P/D therapy in subjects with narrow QRS reporting effects on continuous physiological variables. Twelve studies (2074 patients) met these criteria. Studies were stratified by presence of bias‐resistance steps: the presence of a randomized control arm over a single arm, and blinded outcome measurement. Change in each endpoint was quantified using a standardized effect size (Cohen's d). We conducted separate meta‐analyses for each variable in turn, stratified by trial quality. In non‐randomized, non‐blinded studies, the majority of variables (10 of 12, 83%) showed significant improvement, ranging from a standardized mean effect size of +1.57 (95% CI +0.43 to +2.7) for ejection fraction to +2.87 (+1.78 to +3.95) for NYHA class. In the randomized, non‐blinded study, only 3 out of 6 variables (50%) showed improvement. For the randomized blinded studies, 0 out of 9 variables (0%) showed benefit, ranging from −0.04 (−0.31 to +0.22) for ejection fraction to −0.1 (−0.73 to +0.53) for 6‐minute walk test. Conclusions Differences in degrees of resistance to bias, rather than choice of endpoint, explain the variation between studies of CRT in narrow‐ QRS heart failure addressing physiological variables. When bias‐resistance features are implemented, it becomes clear that these patients do not improve in any tested physiological variable. Guidance from studies without careful planning to resist bias may be far less useful than commonly perceived.

Aims Whether adjusting interventricular (VV) delay changes haemodynamic efficacy of cardiac resynchronization therapy (CRT) is controversial, with conflicting results. This study addresses whether the convention for keeping atrioventricular (AV) delay constant during VV optimization might explain these conflicts. Method and results Twenty-two patients in sinus rhythm with existing CRT underwent VV optimization using non-invasive systolic blood pressure. Interventricular optimization was performed with four methods for keeping the AV delay constant: (i) atrium and left ventricle delay kept constant, (ii) atrium and right ventricle delay kept constant, (iii) time to the first-activated ventricle kept constant, and (iv) time to the second-activated ventricle kept constant. In 11 patients this was performed with AV delay of 120 ms, and in 11 at AV optimum. At AV 120 ms, time to the first ventricular lead (left or right) was the overwhelming determinant of haemodynamics (13.75 mmHg at ±80 ms, P < 0.001) with no significant effect of time to second lead (0.47 mmHg, P = 0.50), P < 0.001 for difference. At AV optimum, time to first ventricular lead again had a larger effect (5.03 mmHg, P < 0.001) than time to second (2.92 mmHg, P = 0.001), P = 0.02 for difference. Conclusion Time to first ventricular activation is the overwhelming determinant of circulatory function, regardless of whether this is the left or right ventricular lead. If this is kept constant, the effect of changing time to the second ventricle is small or nil, and is not beneficial. In practice, it may be advisable to leave VV delay at zero. Specifying how AV delay is kept fixed might make future VV delay research more enlightening.

The British Junior Cardiologists' Association surveyed members to analyse their perception and experience of training. Cardiology trainees perceive significant limitations with the current training structure. This article gives suggestions which could lead to improvements in training and patient care.

Background: Echocardiographic optimization of pacemaker settings is the current standard of care for patients treated with cardiac resynchronization therapy. However, the process requires considerable time of expert staff. The BRAVO study is a non-inferiority trial comparing echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay with an alternative method using non-invasive blood pressure monitoring that can be automated to consume less staff resources. Methods/Design: BRAVO is a multi-centre, randomized, cross-over, non-inferiority trial of 400 patients with a previously implanted cardiac resynchronization device. Patients are randomly allocated to six months in each arm. In the echocardiographic arm, AV delay is optimized using the iterative method and VV delay by maximizing LVOT VTI. In the haemodynamic arm AV and VV delay are optimized using non-invasive blood pressure measured using finger photoplethysmography. At the end of each six month arm, patients undergo the primary outcome measure of objective exercise capacity, quantified as peak oxygen uptake (VO2) on a cardiopulmonary exercise test. Secondary outcome measures are echocardiographic measurement of left ventricular remodelling, quality of life score and N-terminal pro B-type Natriuretic Peptide (NT-pro BNP). The study is scheduled to complete recruitment in December 2013 and to complete follow up in December 2014. Discussion: If exercise capacity is non-inferior with haemodynamic optimization compared with echocardiographic optimization, it would be proof of concept that haemodynamic optimization is an acceptable alternative which has the potential to be more easily implemented. Trial registration: Clinicaltrials.gov NCT01258829

Aims Prognostic benefit from CRT compared with controls is well established. Symptomatic response rates, however, are controversial and have never been systematically evaluated with standard subtraction of control rates to establish the incremental symptomatic response effect of CRT pacing. Methods and results First, we identified 150 consecutive CRT papers and assessed researchers' perceptions of the symptomatic response to CRT. The mean quoted response rate was 66%. Only 26 studies acknowledged the existence of response without the device. Secondly, we examined actual symptomatic response rates in the randomized trials (CARE-HF, COMPANION, CONTAK-CD, MIRACLE, MIRACLE-ICD, MIRACLE-ICD II, MUSTIC, and REVERSE) totalling 3904 patients. The NYHA status improved in 51% of those randomized to CRT vs. 35% of controls (incremental effect 16%). This incremental improvement was significantly greater in open studies (with no device for controls) than in blinded studies (control arm receiving a device but no CRT, such as a defibrillator or a CRT programmed off), 20% vs. 13%, P < 0.001. Conclusions Quoting CRT responder rates in isolation without recognizing spontaneous ‘response’ is common but unwise. The incremental symptomatic response rate from CRT pacing is ∼16%, much lower than widely reported. This value is similar to that for drugs in heart failure and should not be considered disappointing: they both exert powerful prognostic benefits. For scientific purposes, e.g. to explore potential improvements, symptomatic benefit from CRT should be quantified, like all other effects, by comparison with a control.

Background Doubts remain over the use of the ECG in identifying those with increased left ventricular (LV) mass. This is especially so in young individuals, despite their high prevalence of ECG criteria for LV hypertrophy. We performed a study using cardiovascular magnetic resonance (CMR), which provides an in vivo non-invasive gold standard method of measuring LV mass, allowing accurate assessment of electrocardiography as a tool for defining LV hypertrophy in the young. Methods and results Standard 12-lead ECGs were obtained from 101 Caucasian male army recruits aged (mean ± SEM) 19.7 ± 0.2 years. LV mass was measured using CMR. LV mass indexed to body surface area demonstrated no significant correlation with the Cornell Amplitude criteria or Cornell Product for LV hypertrophy. Moderate correlations were seen with the Sokolow-Lyon Amplitude (0.28) and Sokolow-Lyon Product (0.284). Defining LV hypertrophy as a body surface area indexed left ventricular mass of 93 g/m2, calculated sensitivities [and specificities] were as follows; 38.7% [74.3%] for the Sokolow-Lyon criteria, 43.4% [61.4%] for the Sokolow-Lyon Product, 19.4% [91.4%] for Cornell Amplitude, and 22.6% [85.7%] for Cornell Product. These values are substantially less than those reported for older age groups. Conclusion ECG criteria for LV hypertrophy may have little value in determining LV mass or the presence of LV hypertrophy in young fit males.

Objective We examined potential determinants and prognostic value of the corrected QT interval (QTc). Design A total of 4252 British men aged 60 to 79 years had a resting 12-lead electrocardiogram. Potential determinants of the QTc were assessed using multivariable regression. Men were followed up for 7 years. Results A 1 standard deviation increase in QTc (26 milliseconds) was associated with increased all-cause mortality (hazard ratio, 1.13; 95% confidence interval, 1.05-1.22). Longer QTc was associated with increasing age, preexisting coronary heart disease, and a range of drugs. Shorter QTc was present in diabetics and smokers. Corrected QT interval was related inversely with serum potassium and calcium and positively with serum urate, sodium, and systolic blood pressure. The relation of QTc to all-cause mortality was independent of adjustment for these factors. Conclusions Age, preexisting coronary heart disease, certain medications and biochemical factors, and diabetes are independently associated with QTc. Corrected QT interval is an independent predictor of all-cause mortality.

Background Biventricular pacing (CRT) shows clear benefits in heart failure with wide QRS, but results in patients with narrow QRS have been conflicting. In this meta-analysis we tested the hypothesis that trial design might have influenced findings. Method and results We identified all reports of CRT-P/D therapy in subjects with narrow QRS. 12 studies (2074 patients) met the inclusion criteria.Studies were assessed for the presence of bias resistance steps, i.e. a randomised control arm, and blinded outcome measurement. The effect on each endpoint was quantified using a standardised z score (Figure 1). The weighted-mean effect size for CRT studies with no bias resistance features was 0.75 (95% CI 0.45 to 1.05). For those with one feature, randomization but not blinding, it was 0.84 (95% CI -0.14 to 1.81). For those with two features (i.e. blinded, randomised controlled trials), it was -0.02 (95% CI -0.10 to 0.06). Study design had a strong effect on results (p = 0.0007 for contrast between the three groups). Conclusions Only in studies which do not have randomization and full blinding is CRT found to be effective in patients with narrow-QRS heart failure. When randomization and full blinding are implemented, there appears to be no benefit. This is driven by study design, not choice of endpoint. This means that either randomization or blinding inhibit positive physiological effects or that lack of blinding and randomization introduce positive bias unintentionally.

Background The term “resynchronisation” indicates restoration of simultaneity, which by implication refers to ventricular timings (VV delay) rather than atrioventricular (AV) delay. However, while AV delay adjustment causes large haemodynamic effects, different laboratories have reported contradictory results concerning the strength of the effect of VV optimisation. Method and Results 22 patients in sinus rhythm with existing CRT-P/D underwent VV optimisation using non-invasive systolic blood pressure. VV optimisation curves were constructed four ways: (a) atrium to left ventricle delay (A-LV) kept constant, (b) A-RV delay kept constant, (c) time to the first-activated ventricle kept constant, (d) time to the second-activated ventricle kept constant.In 11 patients this was performed with AV delay 120ms, and in 11 at AV-optimum. At AV 120ms, time to the first ventricular lead (left or right) was the overwhelming determinant of haemodynamics (13.75 mmHg at +/- 80ms, p Conclusion Time to the first ventricular activation is the overwhelming determinant of circulatory function, regardless of whether this is the left or right ventricular lead.If this is kept constant, the effect of changing the time to the second ventricle is small or nil, and does not appear to be beneficial.In practice it may be advisable to focus on AV delay optimisation and leave VV delay at zero.

Introduction Left pre-ejection period (LPEP), the interval from onset of ventricular depolarization to the beginning of aortic ejection, is shortened with CRT. We studied the effect of altering AV delay on LPEP in patients with CRT. Methods In 16 patients (12 LBBB, 2 RBBB, 2 narrow QRS) AV delay was adjusted while recording invasive and non-invasive BP simultaneously, and the LPEP measured. Results With optimal pacing, for 11 LBBB patients, LPEP was shorter than at AAI setting suggesting effective delivery of CRT. As their AV delay lengthened, LPEP shortened with a minimum (‘LPEP optimum’) before lengthening again (Figure 1). In RBBB patients, there was a less clear minimum in LPEP just before intrinsic conduction. In patients with narrow QRS, LPEP was always lengthened with pacing. AV delay minimising LPEP was very similar between invasive and non-invasive pressure measurements: SDD 13.6ms, R 2 = 0.92. The LPEP optimum was significantly shorter than the AV optimum maximising BP for both invasive (p = 0.023) and non-invasive (p = 0.0034) pressure measurements in patients with LBBB. Conclusions LPEP is shortened by CRT in patients with LBBB or RBBB. In patients with narrow QRS, LPEP was never lower than with AAI, suggesting a deleterious effect of CRT. AV settings minimising LPEP are shorter than those maximising BP, perhaps because LPEP addresses 1 intra-cardiac component of the CRT effect, while extra-cardiac BP quantifies the final common pathway.

Background Acute haemodynamic measurements can be used for AV delay (AVD) optimisation of cardiac resynchronisation therapy (CRT). It is uncertain whether non-invasive measurements are as reliable as those measured invasively. Methods 37 patients with CRT-P or CRT-D device (86% male, mean age 64 years) had AVD optimisation performed using both invasive and non-invasive systolic blood pressure (SBP) and LV dp/dt max Results There was good concordance between optima obtained using non-invasive SBP, invasive LV and aortic SBP: SDD between 5.7 and 14.1 ms, R 2 between 0.86 and 0.95 (Table 1). In contrast, the optima derived from maximising LV dp/dt max did not agree as well with the other optima: SDD between 28.1 and 29.8 ms, R 2 between 0.58 and 0.65. Of the comparisons in all 36 patients, those between LV dp/dt max and non-invasive SBP (r 2 = 0.58) and between LV dp/dt max and invasive LV SBP (r 2 = 0.62) were worse (p = 0.0067 and 0.013 respectively) than the comparison between non-invasive SBP and invasive LV SBP (r 2 = 0.88). Test re-test reproducibility was better for invasive and non-invasive SBP; invasive LV SBP (SDD 16.8ms, coefficient of variation COV 10.1) non-invasive SBP (SDD 18.3, COV 11.3), compared to invasive LV dp/dt max (SDD 23.6, COV 14.6). Conclusions In this study, we demonstrate good agreement between AVD optimisation performed using non-invasive and invasive systolic blood pressure. LV dp/dt max showed relatively poor correlation with the AVD optima determined using SBP which is most likely due to a larger noise component in LV dp/dt max measurements.