Impact of COVID-19 lockdown in patients with implantable cardioverter and cardiac resynchronization therapy defibrillators: insights from daily remote monitoring transmissions.

In Italy, a strict lockdown was imposed from 8 March 2020 to stop the spread of the coronavirus disease 2019 (COVID-19). We explored the effect of this lockdown on data transmitted by remote monitoring (RM) of implantable cardioverter and cardiac resynchronization therapy defibrillators (ICDs/CRT-Ds). RM daily transmissions from ICDs and CRT-Ds were analyzed and compared in two consecutive 1 month frames pre and post-lockdown: period I (7 February-7 March 2020) and period II (8 March-7 April 2020). The study cohort included 180 patients (81.1% male, 63.3% ICDs and 36.7% CRT-Ds) with a median age of 70 (interquartile range 62-78) years. The median value of physical activity provided by accelerometric sensors showed a significant reduction between period I and II [13.1% (8.2-18.1%) versus 9.4% (6.3-13.8%), p < 0.001]. Eighty nine % of patients decreased their activity, for 43.3% the relative reduction was ≥ 25%. The mean heart rate decreased significantly [69.2 (63.8-75.6) bpm vs 67.9 (62.7-75.3) bpm, p < 0.001], but with greater reduction (≈3 beats/minute) in patients aged < 70 years. Resting heart rate and thoracic impedance showed minor variations. No differences were observed in device pacing % and arrhythmias. In cardiac patients, the lockdown imposed to contain COVID-19 outbreak significantly reduced the amount of physical activity and the mean heart rate. These side effects of in-home confinement quarantine should be taken in consideration for frail patients.

Remote monitoring temporal trends during COVID-19 pneumonia in patients with implanted defibrillators.

It is unknown whether some of the clinical parameters transmitted by remote monitoring (RM) of cardiac implanted devices could show recurrent patterns caused by COVID-19 infection. Our aim was to describe RM daily temporal trends for implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) recipients during COVID-19 infection. A 65-year-old woman with a CRT-D had a sudden increase of approximately 15 bpm and 10 bpm in nocturnal and mean heart rate, respectively, 11 days before hospitalization for COVID-19 pneumonia. At the same time physical activity decreased progressively and continuously. A 78-year-old woman with an ICD showed significant changes in RM trends starting from the COVID-19-related symptoms: strong decrease in physical activity, progressive increase in mean and nocturnal heart rate, irregular trend of heart rate variability, and rapid drop in thoracic impedance. Two months later, on hospitalization, computed tomography showed a "crazy-paving" pattern of the lungs, which is a clinical picture of COVID-19 pneumonia with concomitant pleural effusion. .

Severe Spontaneous Echo Contrast/Auricolar Thrombosis in "Nonvalvular" AF: Value of Thromboembolic Risk Scores.

BACKGROUND: Patients with atrial fibrillation (AF) have an increased thromboembolic risk that can be estimated with risk scores and sometimes require oral anticoagulation therapy (OAT). Despite correct anticoagulation, some patients still develop left atrial spontaneous echo contrast (SEC) or thrombosis. The value of traditional risk scores (R2 CHADS2 , CHADS2 , and CHA2 DS2 -VASc) in predicting such events remains controversial. METHODS AND RESULTS: The aim of our study was to explore variables linked to severe SEC or atrial thrombosis and evaluate the performance of traditional risk scores in identifying these patients. In order to do this, we retrospectively analyzed 568 patients with nonvalvular nonparoxysmal AF who underwent electrical cardioversion from January 2011 to December 2016 after OAT for a minimum of 4 weeks. A transesophageal echocardiogram was performed in 265 patients for various indications, and 24 exhibited left atrial SEC or thrombosis. Female gender, history of heart failure or left ventricular ejection fraction <40%, and high levels (>1 mg/dL) of C-reactive protein (CRP) were independently associated with left atrial SEC/thrombosis. A score composed by these factors (denominated HIS [Heart Failure, Inflammation, and female Sex]) showed a sensitivity of 79% and a specificity of 60% (area under receiver operating characteristic curve 0.695, P = 0.002) in identifying patients with a positive transesophageal echo; traditional risk scores did not perform as well. CONCLUSIONS: In patients with persistent AF and suboptimal anticoagulation, a risk score composed by history of heart failure, high CRP, and female gender identifies patients at high risk of left atrial SEC/thrombosis when its value is >1.

Electrocardiographic criteria of true left bundle branch block: a simple sign to predict a better clinical and instrumental response to CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) has proved to be very effective in improving morbidity and mortality in patients affected with severe congestive heart failure. Its efficacy has been shown to be greater in patients with left bundle branch block (LBBB). The aim of our study was to verify if newly proposed criteria for true LBBB identify patients with a better clinical and instrumental response to CRT. METHODS: Between May 2007 and April 2011, 111 patients with left ventricular ejection fraction (LVEF) ≤ 35% and LBBB morphology received a CRT device and were divided into two groups according to QRS morphology. Group 1 (61 patients) consisted of patients with "true" LBBB morphology; group 2 (50 patients) consisted of patients with "false" LBBB. The primary endpoint was the utility of criteria for true LBBB to predict a composite endpoint of all-cause mortality and hospital admission with heart failure. The secondary endpoint was the utility of the same criteria to predict an absolute increase in LVEF ≥ 10%. RESULTS: "False" LBBB morphology and a dose of bisoprolol <5 mg at last follow-up were the only parameters related to clinical outcome in multivariate analysis (respectively: hazard ratio [HR] 3.98, confidence interval [CI] 95% 1.51-10.48; HR 0.15, CI 95% 0.05-0.43). "True" LBBB morphology was the only variable significantly related to a greater increase in LVEF (HR 4.57, CI 95% 1.36-8.28). CONCLUSION: True LBBB morphology is related to a higher event-free survival rate in CRT patients and better echocardiographic response.

Effect of remodelling, stretch and ischaemia on ventricular fibrillation frequency and dynamics in a heart failure model.

OBJECTIVE: The dynamics of ventricular fibrillation (VF) in the presence of heart failure (HF) are different from those in the normal heart. This has been attributed solely to HF-induced electrophysiologic remodelling. We hypothesized that acute stretch and ischaemia, which are normally present during VF, might contribute significantly to the altered VF dynamics in HF. METHODS: HF was induced in eight sheep by rapid ventricular pacing for 4-6 weeks. Eight sheep served as controls. Optical mapping of isolated hearts was performed during VF at low intraventricular pressure (0-5 mm Hg), high pressure (25-30 mm Hg, in six HF and six controls), and at low pressure after 5 min of global ischaemia (six HF, five controls). Maximum dominant frequency (DF(max)), singularity point (SP) density and number of SP lasting more than one revolution (rotors) were analyzed. Possible statistical interactions between HF and ischaemia (HF x ischaemia) or stretch (HF x stretch) were evaluated. RESULTS: At low pressure, VF in HF was slower (13% reduction in DF(max)) and more organized than in control: 33% less SPs and 74% less rotors with 20% longer life spans. Acute stretch did not affect DF(max) but increased SP and rotors density similarly in both groups (no interaction HF x stretch). In controls, ischaemia caused a marked decrease in DF(max), SP density and incidence of rotors. However, in HF animals, the ischaemia-induced decrease in SP density was virtually abolished, indicating a significant interaction HF x ischaemia (p<0.005). CONCLUSIONS: HF remodelling decreases VF rate and increases VF organization. Acute stretch partially reverses these effects by a mechanism that is independent of remodelling. The effects of acute ischaemia on VF dynamics are significantly attenuated in HF compared to normal hearts.

From mouse to whale: a universal scaling relation for the PR Interval of the electrocardiogram of mammals.

BACKGROUND: On the ECG, the PR interval measures the time taken by an electrical impulse generated in the sinoatrial node to propagate from atria to ventricles. From mouse to whale, the PR interval increases approximately 10(1), whereas body mass (BM) augments approximately 10(6). Scaling of many biological processes (eg, metabolic rate, life span, aortic diameter) is described by the allometric equation Y=Y(0) x BM(b), where Y is the biological process and b is the scaling exponent that is an integer multiple of 1/4. Hierarchical branching networks have been proposed to be the underlying mechanism for the 1/4 power allometric law. METHODS AND RESULTS: We first derived analytically the allometric equation for the PR interval. We assumed that the heart behaves as a set of "fractal-like" networks that tend to minimize propagation time across the conducting system while ensuring a hemodynamically optimal atrioventricular activation sequence. Our derivation yielded the relationship PR proportional, variant BM1/4. We subsequently obtained previously published values of PR interval, heart rate, and BM of 541 mammals representing 33 species. Double-logarithmic analysis demonstrates that PR interval increases as heart rate decreases, and both variables relate to BM following the 1/4 power law. Most important, the best fit for PR versus BM is described by the equation PR=53 x BM0.24. Hence, the empirically determined exponent (0.24) is close to 1/4, as predicted. CONCLUSIONS: We have demonstrated that the PR interval of mammals scales as the 1/4 power of the BM, following the universal law for allometric scaling to ensure an optimal atrioventricular activation sequence.

[Usefulness and limitations of contrast echocardiography during dobutamine stress test]. / Utilità e limiti dell'ecocontrastografia durante eco-stress con dobutamina.

BACKGROUND: The aim of this study was to evaluate whether the use of contrast agent in addition to second harmonic imaging during dobutamine stress echocardiography can improve endocardial visualization and interobserver agreement in the evaluation of regional wall motion in patients with suboptimal or poor acoustic window. METHODS: Twenty-one patients with a poor or suboptimal acoustic window underwent dobutamine stress echocardiography. Echocardiographic images in parasternal long-axis and short-axis, apical 4-chamber and 2-chamber views were cine-looped at baseline and peak stress before and after injection of contrast medium (Levovist at a concentration of 400 mg/ml). Endocardial visualization and regional wall motion were evaluated by two blinded observers. RESULTS: The contrast medium improved segment visualization both at baseline (complete visualization in 74% of segments with contrast vs 71% without, p = NS) and at peak stress (76 vs 64%, p < 0.001). Contrast medium improved significantly segment visualization in apical 4-chamber view both at baseline (complete visualization in 87% of segments with contrast vs 72% without, p < 0.01) and at peak (89 vs 66%, p < 0.001) and in apical 2-chamber view both at baseline (81 vs 61%, p < 0.001) and at peak (89 vs 55%, p < 0.001). When individual segments were analyzed, endocardial visualization improved significantly in all segments of the anterior wall and in the mid and distal segments of the lateral wall both at baseline and at peak stress. The use of contrast medium did not improve significantly interobserver agreement in the evaluation of regional wall motion at peak stress (k = 0.63 vs 0.67 without and with contrast, respectively). CONCLUSIONS: The use of Levovist during dobutamine stress echocardiography improves significantly segment visualization in the apical views both at baseline and at peak stress and increases interobserver agreement in the evaluation of regional wall motion at peak stress.

Noninvasive estimation of both systolic and diastolic pulmonary artery pressure from Doppler analysis of tricuspid regurgitant velocity spectrum in patients with chronic heart failure.

BACKGROUND: Noninvasive estimation of pulmonary artery systolic and diastolic pressures usually requires the investigation of both tricuspid and pulmonary regurgitant jets and an estimate of right atrial pressure. A new, noninvasive method to obtain pulmonary diastolic pressure (based on the hemodynamic demonstration that right ventricular systolic pressure and pulmonary artery diastolic pressure are equal at the time of pulmonary valve opening) from the analysis of tricuspid regurgitation alone has been described in a small cohort of patients. We sought to verify the accuracy of this method in a large population of patients with heart failure. METHODS: An estimate of pulmonary artery diastolic pressure was obtained by transposing the pulmonary opening time (from the onset of the R wave on the electrocardiographic tracing to the beginning of pulmonic forward flow on Doppler examination) onto the tricuspid regurgitant velocity curve and calculating the pulmonary artery diastolic pressure value as the pressure gradient between the right ventricle and right atrium at this time. The study group included 86 consecutive patients (64 men, aged 52 +/- 11 years) with heart failure (New York Heart Association class > or =II, 94%) who were in stable clinical condition with a chiefly idiopathic (57%), ischemic (24%), or other form (13%) of dilated cardiomyopathy. Noninvasive, right-sided pressures were compared with invasive measurements obtained during right heart catheterization performed within 24 hours. The Bland and Altman graphic method was used together with the calculation of the Lin concordance correlation coefficient and its 95% CI to assess the agreement between hemodynamic and echocardiographic measurements. RESULTS: Catheter-derived pulmonary artery systolic pressure ranged from 8 to 119 mm Hg (mean 42 +/- 21 mm Hg), pulmonary artery diastolic pressure from 1 to 59 mm Hg (mean 20 +/- 11 mm Hg), and right atrial pressure from -5 to 20 mm Hg (mean 6 +/- 5 mm Hg). Tricuspid regurgitation was detected in 75 of 86 patients (87%). Pulmonary artery systolic pressure ranged from 13 to 110 mm Hg (mean 44 +/- 21 mm Hg); the pressure gradient between the right ventricle and right atrium at time t of the pulmonary valve opening on the tricuspid regurgitation velocity curve was measurable in 70 of 75 (93%) cases and ranged from 3.5 to 64 mm Hg (mean 22 +/- 11 mm Hg). Good agreement was observed not only for pulmonary artery systolic pressure but also for pulmonary artery diastolic pressure, based on the analysis of the tricuspid regurgitation velocity jet, with a slight difference between measurements (-1.8 and 0.1, respectively), no evident pattern of point scattering, and a high concordance correlation coefficient that was elicited by the virtually total overlapping of lines on the graph. Overall results were not significantly different whether patients with depressed right ventricular function (right ventricular ejection fraction < or =35%), with a tricuspid regurgitation grade > or =2 and atrial fibrillation were included in the analysis. CONCLUSIONS: The narrow paired difference for the estimate of pulmonary artery systolic pressure and the even better difference for pulmonary artery diastolic pressure using the tricuspid regurgitation velocity curve analysis indicates that this new method reliably estimates invasive right-sided pressures over a wide range of pressure values in patients with heart failure. The overall good correlation with invasive values indicates that Doppler examination of tricuspid regurgitation alone may provide a simple and comprehensive new method for the noninvasive evaluation of right ventricular and pulmonary hemodynamics in patients with heart failure.