Hospital attendance and admission trends for cardiac diseases during the COVID-19 outbreak and lockdown in Greece.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) outbreak, along with implementation of lockdown and strict public movement restrictions, in Greece has affected hospital visits and admissions. We aimed to investigate trends of cardiac disease admissions during the outbreak of the pandemic and possible associations with the applied restrictive measures. STUDY DESIGN: This is a retrospective observational study. METHODS: Data for 4970 patients admitted via the cardiology emergency department (ED) across 3 large-volume urban hospitals in Athens and 2 regional/rural hospitals from February 3, 2020, up to April 12 were recorded. Data from the equivalent (for the COVID-19 outbreak) time period of 2019 and from the postlockdown time period were also collected. RESULTS: A falling trend of cardiology ED visits and hospital admissions was observed starting from the week when the restrictive measures due to COVID-19 were implemented. Compared with the pre-COVID-19 outbreak time period, acute coronary syndrome (ACS) [145 (29/week) vs. 60 (12/week), -59%, P < 0.001], ST elevation myocardial infarction [46 (9.2/week) vs. 21 (4.2/week), -54%, P = 0.002], and non-ST elevation ACS [99 cases (19.8/week) vs. 39 (7.8/week), -60% P < 0.001] were reduced at the COVID-19 outbreak time period. Reductions were also noted for heart failure worsening and arrhythmias. The ED visits in the postlockdown period were significantly higher than in the COVID-19 outbreak time period (1511 vs 660; P < 0.05). CONCLUSION: Our data show significant drops in cardiology visits and admissions during the COVID-19 outbreak time period. Whether this results from restrictive measures or depicts a true reduction of cardiac disease cases warrants further investigation.

Antianginal Efficacy of Ivabradine in Patients With History of Coronary Revascularization.

Although coronary revascularization procedures are widely performed in patients with coronary artery disease (CAD), angina is often reported, even after such procedures. This study evaluated the antianginal efficacy and effect of ivabradine treatment on quality of life (QOL) in patients with CAD and history of coronary revascularization. This is a post hoc analysis (926 post-revascularization patients) of a prospective, noninterventional study, which included 2403 patients with CAD and stable angina. The data were recorded at baseline, at 1 month and 4 months after inclusion. After ivabradine administration, mean number of anginal events decreased from 2.2 ± 2.3 (median: 2.0, minimum: 0.0, maximum: 21.0, range: 21.0) to 0.3 ± 0.6 (median: 0.0, minimum: 0.0, maximum: 7.0, range: 7.0) times/week (P < .001), while nitroglycerin consumption decreased from 1.5 ± 2.2 (median: 1.0, minimum: 0.0, maximum: 20.0, range: 20.0) to 0.1 ± 0.4 times/week (median: 0.0, minimum: 0.0, maximum: 5.0, range: 5.0; P < .001). Quality of life improved at study completion compared to baseline (P < .001). Ivabradine addition on top of optimal individualized dose of ß-blockers is associated with decreased anginal events and improvement in QOL in patients with stable angina and history of coronary revascularization.

Prevention of atrial fibrillation by inter-atrial septum pacing guided by electrophysiological testing, in patients with delayed interatrial conduction.

AIMS: Interatrial septum (IAS) pacing seems efficient in synchronizing atrial depolarization in patients (pts) with delayed inter-atrial conduction, but its clinical role in preventing atrial tachyarrhythmias is still debated. This study was conducted in order to evaluate the clinical efficacy of IAS pacing guided by pace mapping of the IAS, as an alternative treatment modality in pts with drug refractory paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: We evaluated 29 pts (13 male, 16 female, 60 +/- 11 years), with drug refractory PAF, normal sinus node function and prolonged inter-atrial conduction time (P wave 142 +/- 10 ms). Multipolar catheters were inserted and the electrograms from the high right atrium (HRA) and proximal, middle and distal coronary sinus (CS) were recorded. The IAS was paced from multiple sites. The site of IAS where the timing between HRA and distal CS was <20 ms was considered the most suitable for synchronizing the atria. This site was found to be superior to the CS os. near the fossa ovalis in all pts. An active fixation atrial lead was positioned at this site and a standard lead was placed in the right ventricle. During IAS pacing, the P wave duration decreased significantly to 107 +/- 15 ms (P<0.001). At implant, the atrial sensing was 2.3 +/- 0.7 mV, the atrial pacing threshold was 0.95 +/- 0.15 V (0.5 ms) and the impedance was 760 +/- 80 Ohm. We evaluated the pts during four periods of 3 months duration each. The first period (control) was before pacemaker implantation, while the pts were under antiarrhythmic treatment. During the subsequent two periods, we evaluated the clinical efficacy of IAS pacing to prevent PAF recurrences, in AAT (75 bpm) and AAIR (75-140 bpm) mode, with random selection of the order and after discontinuation of antiarrhythmic treatment. During the fourth period, the same AAIR mode was assessed, but antiarrhythmic drugs were also administered. We compared the arrhythmia free interval among the four periods. The proportion of atrial paced beats in AAIR pacing mode plus antiarrhythmics was significantly higher compared with the drug-free period in AAIR mode (57 +/- 9% and 49 +/- 9% respectively, P=0017) and with AAT pacing mode (44 +/- 10%,(, P<0.001). In AAT mode, the arrhythmia free interval was 24.2 +/- 5.1 days, while it was 26.2 +/- 5.7 days in AAIR mode. These intervals did not differ significantly from the pre-implantation period (24.1 +/- 6.3 days). The arrhythmia free interval in AAIR pacing in combination with antiarrhythmic drug therapy was 38.7 +/- 8.1 days and this was significantly longer than the previous periods (P<0.05). CONCLUSION: Atrial septal pacing in combination with antiarrhythmic drug therapy reduced the incidence of PAF in pts with prolonged inter-atrial conduction times. Pace mapping of the IAS is an attractive technique to assess the shortest atrial activation time between HRA and distal CS. Whether placement of the atrial lead based on the shortest HRA--distal CS time is the best place in the IAS to prevent PAF still remains to be proven.

Modulation of the sympathovagal balance in drug refractory dilated cardiomyopathy, treated with permanent atrioventricular sequential pacing.

The aim of this study was to assess the long term efficacy of DDD pacing mode in selected patients with idiopathic dilated cardiomyopathy (IDCM) and drug refractory heart failure. The patients were evaluated according to the long term alteration of the sympathovagal balance (SVB). Patients with IDCM were considered eligible for DDD pacing if during temporary VDD pacing a 15% or more increase in the resting cardiac output was demonstrated. From the 29 patients studied, finally 20 patients (15M, 5F, 69 +/- 10 years) fulfilled the aforementioned criterion and therefore were considered candidates for permanent DDD pacing (NYHA class: 3.5 +/- 0.3, Ejection fraction: 27 +/- 7%, Resting cardiac index (CI) 2.6 +/- 0.4 l/min). The ECG of the patients demonstrated LBBB in 13, RBBB in 4 and RBBB + LAH in 3, with a PR interval of 232 +/- 28 ms and QRS duration of 138 +/- 15 ms. The pacemaker was programmed at 40-150 bpm, and AV delay of 105 +/- 20 ms. The lower heart rate programmed, in conjunction with the heart failure state of these patients, was responsible for essentially continuous atrial tracking, ventricular pacing. We evaluated the SVB in the pre- and post-implant periods (3rd and 6th month), using the hourly power spectral analysis (PSA) of heart rate variability during 24 hour Holter monitoring. As SVB we considered the ratio: low (0.04-0.15 Hz) to high frequency (0.15-0.40 Hz). We compared the SVB (LF/HF) during the day and night time for the pre- and post-implant periods. Post-pacing, the NYHA class was significantly improved (2.9 +/- 0.2 and 2.7 +/- 0.3 the 3rd and 6th month respectively). The mean heart rate was 78 +/- 8 bpm in the 3rd and 80 +/- 7 bpm in the 6th month postoperatively, which was lower than the 84 +/- 9 bpm preoperatively, but this difference did not reach statistical significance. During the night time the LF/HF decreased from 1.45 +/- 0.2 (LF: 7.19 +/- 0.43, HF: 4.95 +/- 0.54) in the pre-implant period to 0.9 +/- 0.09 (p < 0.001) (LF: 6.96 +/- 0.63, HF: 7.73 +/- 0.48) in the 3rd month. No further changes were observed in the 6th month (0.82 +/- 0.05, p = NS) (LF: 6.83 +/- 0.51, HF: 8.53 +/- 0.86) compared to the 3rd month. During the day time the LF/HF decreased from 1.5 +/- 0.5 (LF: 7.87 +/- 0.67, HF: 5.24 +/- 0.32) to 1.43 +/- 0.6 (p = NS) (LF: 7.34 +/- 0.71, HF: 5.24 +/- 0.42) in the 3rd month and to 1.41 +/- 0.09 in the 6th month (p = NS) (LF: 7.51 +/- 0.74, HF: 5.36 +/- 0.63). Comparing the LF/HF of day and the night time period, while in the pre-implant period there was no significant difference (1.5 +/- 0.5 vs 1.45 +/- 0.2, p = NS), the difference became significant in the 3rd (1.43 +/- 0.6 vs 0.9 +/- 0.09, p < 0.001) and 6th month (1.41 +/- 0.09 vs 0.82 +/- 0.05, p < 0.001). In conclusion, DDD pacing with individualized AV delay as an adjunct therapy could be a valuable method in selected patients with IDCM and drug refractory heart failure. DDD pacing improves the SVB over the long term. This improvement is attributed to sympathetic activity withdrawal and is more pronounced during night and less during day time.

Implantable cardioverter defibrillator-an unusual case of inappropriate discharge during showering.

The evolution of diagnostic information provided in implantable cardioverter defibrillators (ICDs) has paralleled the advances in the therapeutic options incorporated in these systems. Contemporary devices are capable of providing recordings of electrical events surrounding all delivered and aborted device therapy. This report presents un unusual case of inappropriate discharge of an ICD, resulting from electromagnetic interference. A transvenous ICD system (Sentry Hot Can 4310 HC, Telectronics Denver, CO), was implanted in a patient with ischemic heart disease due to episodes of ventricular tachycardia refractory to antiarrhythmic treatment. One month post-implant the patient reported two consecutive shocks from the device while showering. The non-physiological cycle length (100 ms) recorded in conjunction to the scenario of the event, raised the suspicion of electromagnetic interference through electrical current leakage in the bathroom, an hypothesis that was subsequently proved. This case report underscores that electromagnetic interference can become hazardous in common daily activities of patients with an ICD.

Right posterior atrioventricular ring: a location for different types of atrioventricular accessory connections.

We present an unusual case of a 28-year-old female patient with recurrent episodes of tachycardias due to participation of two accessory connections located in the posterior tricuspid annulus. Both connections were of the atrioventricular type, the one with non decremental fast conducting properties at the right posteroseptal area, the other with node-like properties at the posterolateral tricuspid ring. Both pathways were successfully ablated transvenously with radiofrequency energy application at the same session. Implications about a common embryological origin of the two pathways as well as review of the literature for similar cases are presented.

Ventricular performance and quality of life in patients who underwent radiofrequency AV junction ablation and permanent pacemaker implantation due to medically refractory atrial tachyarrhythmias.

UNLABELLED: In patients with drug refractory atrial tachyarrhythmias and previous failed attempts of ablation of the arrhythmia substrate, radiofrequency (RF) modulation or ablation of the atrioventricular (AV) junction is an alternative procedure. AIM: Of this study was to assess the efficacy and long term results of RF AV junction ablation in conjunction with permanent pacemaker implantation, in the management of patients with drug resistant atrial tachyarrhythmias. METHODS: Between 4/92 and 1/97, 46 patients (30 male, 16 female, 67 +/- 12 years) underwent RF AV junction ablation because of paroxysmal atrial fibrillation (24 patients), chronic atrial fibrillation (13 patients), atrial flutter (5 patients) and atrial tachycardia (4 patients). The underlying heart disease was dilated cardiomyopathy (16), ischemic heart disease (9), hypertensive heart disease (6), hypertrophic cardiomyopathy (3), atrial septal defect (2) and non structural heart disease (10). The duration of symptoms was 6.4 +/- 3.5 years at a maximal heart rate 169 +/- 24 bpm. The hospital admissions in the last 12 months were 8.2 +/- 3 per patient. The failed antiarrhythmic drugs were 3.5 +/- 2.1. The functional NYHA class was 2.7 +/- 0.6. Patients with atrial flutter and atrial tachycardia had previous failed attempts of RF ablation of the arrhythmia substrate. Thirty patients had a compromised left ventricular systolic function with LVEF below 50% (mean 34 +/- 9%). AV junction ablation was achieved in all patients after 4 +/- 2.5 RF applications. Post ablation, the selected pacing mode was DDD-R for the 33 patients with paroxysmal atrial tachyarrhythmias and VVI-R for the 13 pts with chronic atrial fibrillation. The dual chamber pacemakers implanted had the option of automatic mode switch. RESULTS: During the follow-up period of 28 +/- 13 months (6-47), AV conduction recovered in 1 patient. Antiarrhythmic treatment was necessary in only 7 patients. Post ablation the new functional NYHA class was 1.4 +/- 0.8 (p < 0.001). Post ablation hospital admissions, including ordinary pacemaker follow-up visits, were 4 +/- 1 per patient per year (p < 0.001). Six months after the procedure the LVEF of the study population was increased from 42 +/- 16% to 50 +/- 14% (p = NS). In the 30 patients with heart failure the LVEF was significantly increased to 46 +/- 8% (p < 0.05). Symptomatic relief or significant improvement was observed in all patients as showed by the answers given in a customized questionnaire before and after the procedure. CONCLUSIONS: In patients with drug refractory atrial tachyarrhythmias, RF AV junction ablation and permanent pacemaker implantation is an alternative therapy with excellent long term results in terms of arrhythmia control, ventricular performance and quality of life.

Atrial septal pacing to synchronize atrial depolarization in patients with delayed interatrial conduction.

The current method of pacing the right atrium from the appendage or free wall is often the source of delayed intraatrial conduction and discoordinate left and right atrial mechanical function. Simultaneous activation of both atria with pacing techniques involving multisite and multilead systems is associated with suppression of supraventricular tachyarrhythmias and improved hemodynamics. In the present study we tested the hypothesis that pacing from a single site of the atrial septum can synchronize atrial depolarization. Five males and two females (mean age 58 +/- 6 years) with drug refractory paroxysmal atrial fibrillation (AF) were studied who were candidates for AV junctional ablation. All patients had broad P waves (118 +/- 10 ms) on the surface ECG. Multipolar catheters were inserted and the electrograms from the high right atrium (HRA) and proximal, middle, and distal coronary sinus (CS) were recorded. The atrial septum was paced from multiple sites. The site of atrial septum where the timing between HRA and distal CS (d-CS) was < or = 10 ms was considered the most suitable for simultaneous atrial activation. An active fixation atrial lead was positioned at this site and a standard lead was placed in the ventricle. The interatrial conduction time during sinus rhythm and AAT pacing and the conduction time from the pacing site to the HRA and d-Cs during septal pacing were measured. Atrial septal pacing was successful in all patients at sites superior to the CS o.s. near the fossa ovalis. During septal pacing the P waves were inverted in the inferior leads with shortened duration from 118 +/- 10 ms to 93 +/- 7 ms (P < 0.001), and the conduction time from the pacing site to the HRA and d-CS was 54.3 +/- 6.8 ms and 52.8 +/- 2.5 ms, respectively. The interatrial conduction time during AAT pacing was shortened in comparison to sinus rhythm (115 +/- 18.9 ms vs 97.8 +/- 10.3 ms, P < 0.05). In conclusion, simultaneous activation of both atria in patients with prolonged interatrial conduction time can be accomplished by pacing a single site in the atrial septum using a standard active fixation lead placed under electrophysiological study guidance. Such a pacing system allows proper left AV timing and may prove efficacious in preventing various supraventricular tachyarrhythmias.

Circadian modulation of ventricular tachycardia cycle length variability in ICD patients with dilated cardiomyopathy.

VT is usually characterized by stability of the RR intervals after a few cycles from the onset. The aim of this study was to evaluate the VT cycle length (VTCL) variability in patients with dilated cardiomyopathy (DCM), in whom a third-generation ICD was previously implanted. Eighty-three episodes of VT were analyzed in 10 patients (8 male, 2 female, 65 +/- 6 years) with DCM, and NYHA Class II (7 patients) or III (3 patients). As an index of VTCL variability, the coefficient of variance of the last 15 consecutive RR intervals (CVRR) of the detected and stored VT by the device was considered. The mean value of the RR intervals and the mean value of CVRR of the VT episodes recorded during day versus night time were compared. Fifty-five VT episodes were recorded during the day and 28 episodes during the night time. The mean RR intervals of VT episodes during day time was 335 +/- 29 ms and during the night time was 350 +/- 22 ms (P = NS). The mean CVRR of VT episodes during day time and night time were 2.83 +/- 0.52 and 3.36 +/- 0.48, respectively (P = 0.017). In conclusion, a circadian modulation of VTCL variability exists in patients with DCM. The VTCL variability is less during day time compared to night time. A possible explanation is a circadian alteration of sympathovagal balance modifying the electrophysiological properties of the arrhythmogenic substrate.

Congestive heart failure and VVI pacing mode: dynamic behavior of the dispersion of ventricular repolarization.

Dynamic Behavior of the Dispersion of Ventricular Repolarization. The aim of this study was to evaluate the circadian variation in the spatial dispersion of ventricular repolarization in continuously paced patients with congestive heart failure (CHF). Fourteen patients (10 males, 4 females, aged 65 +/- 8 years) with CHF due to dilated cardiomyopathy (DCM) and an echocardiographic ejection fraction of 28% +/- 3% were studied. All patients underwent AV junctional RF ablation and permanent pacemaker implantation for drug refractory chronic atrial fibrillation (AF). Patients were evaluated at 1 month postimplant with a three-channel 24-hour Holter monitor, using the three plane Frank orthogonal leads (X, Y, and Z), in VVI pacing mode at 70 beats/min. For each hour, the mean value of spike-T interval dispersion of the first five beats was measured. The control group consisted of 20 patients without structural heart disease, but with AF and complete AV block, continuously paced in VVI mode at 70 beats/min. The dispersion of the spike-T interval had a circadian behavior in the study population, with higher values at night and lower during the daytime. During the daytime, the mean value of spike-T interval dispersion was 39 +/- 5 ms and during the nighttime it was 45 +/- 7 ms (P = 0.003). Such a difference between day and night was not found in the control group (38 +/- 6 ms and 40 +/- 8 ms, respectively, P = NS). In the daytime period the mean value of spike-T interval dispersion of our study population was comparable to that of the control group (P = NS), while during the nighttime it was significantly higher (P = 0.0004). In conclusion, by evaluating the dispersion of ventricular repolarization in two dimensions, space and time, a circadian variation was found in paced patients with CHF due to DCM. The increased QT dispersion in these patients during the nighttime period was attributed to different effects of vagal activity in normal and abnormal myocardial areas.

Clinical characteristics and electrophysiologic properties of atrioventricular accessory pathways: importance of the accessory pathway location.

OBJECTIVES: This study was designed to assess the influence of accessory atrioventricular (AV) pathway location on the clinical and electrophysiologic characteristics of 384 consecutive symptomatic patients having a single accessory pathway. METHODS: Four locations were studied: left free wall (n = 270), posteroseptal (n = 52), anteroseptal (n = 29) and right free wall (n = 33). Ten clinical variables and 12 electrophysiologic variables were analyzed, including the effective refractory period of the accessory pathway and the different clinically occurring and inducible arrhythmias. RESULTS: Only two clinical findings were associated with accessory pathway location: 1) later age at onset of symptoms in the left free wall versus other accessory pathway locations (24 +/- 12 vs. 20 +/- 11 years, p = 0.02), and 2) later age at the time of electrophysiologic study in the left free wall accessory pathway location (36 +/- 13 vs. 32 +/- 11 years, p = 0.01). Six electrophysiologic variables showed a correlation with the accessory pathway location: 1) retrograde conduction only was found less frequently in right free wall (9%) and anteroseptal (10%) than in left free wall (26%) and posteroseptal (29%) accessory pathway locations (p = 0.05); 2) the retrograde effective refractory period of the accessory pathway was shorter in anteroseptal (253 +/- 52 ms) and left free wall (270 +/- 72 ms) as compared with right free wall (296 +/- 101 ms) and posteroseptal (301 +/- 76 ms) locations (p = 0.05); 3) retrograde decremental conduction over the accessory pathway was present in the posteroseptal (17%) and left free wall (3%) but absent in the other locations (p less than 0.001); 4) anterograde decremental conduction was only seen in the right free wall location (12%) (p less than 0.001); 5) orthodromic reentrant tachycardia was induced less frequently in the right free wall than in other locations (70% vs. 93%, p less than 0.001); and 6) inducibility of atrial fibrillation was greater in anteroseptal (62%) than in right free wall (21%), left free wall (44%) and posteroseptal (36%) locations (p = 0.01). CONCLUSIONS: The location of the accessory AV pathway is associated with specific electrophysiologic characteristics.