Many patients who suffer from bradycardia and need cardiac pacing also have atrial fibrillation (AF). New pacemaker algorithms, such as atrial preventive pacing and atrial antitachycardia pacing ...(DDDRP) and managed ventricular pacing (MVP), have been specifically designed to reduce AF occurrence and duration and to minimize the detrimental effects of right ventricular pacing. The randomized MINimizE Right Ventricular pacing to prevent Atrial fibrillation and heart failure trial established that DDDRP + MVP pacing modality reduced permanent AF in bradycardia patients as compared with standard dual-chamber pacing (DDDR).
The aim of this study was to estimate the cost savings due to lower AF-related health care utilization events based on health care costs from the United States and the European Union.
Dual-chamber pacemaker patients with a history of paroxysmal or persistent AF were randomly assigned to receive DDDR (n = 385) or the advanced features (DDDRP + MVP; n = 383). We used published health care costs from the United States and the European Union (Italy, Spain, and the United Kingdom) to estimate the costs associated with AF-related hospitalizations and emergency visits.
The rate of AF-related hospitalizations was significantly lower in the DDDRP + MVP group than in the conventional pacemaker group (DDDR group; 42% reduction; incidence rate ratio 0.58). Similarly, a significant reduction of 68% was observed for AF-related emergency department visits (incidence rate ratio 0.32; P < .001). As a consequence, DDDRP + MVP could potentially reduce health care costs by 40%-44%. Over a ten-year period, the cost savings per 100 patients ranged from $35,702 in the United Kingdom to $121,831 in the United States.
New pacing algorithms such as DDDRP + MVP used in the MINimizE Right Ventricular pacing to prevent Atrial fibrillation and heart failure trial successfully reduced AF-related health care utilization, resulting in significant cost savings to payers.
Abnormalities in cardiac rhythm are caused by disorders of impulse generation, conduction, or a combination of the 2, and may be life-threatening because of a reduction in cardiac output or ...myocardial oxygenation. Cardiac arrhythmias are commonly classified as tachycardias (supraventricular or ventricular) or bradycardias. Bradycardias are uncommon in the critically ill patient and often are caused by an underlying reversible disorder (eg, hyperkalemia, drug toxicity). Supraventricular and ventricular tachycardias are more often encountered in the critically ill patient and often have underlying treatable disorders that precipitate their development (eg, hypokalemia, hypomagnesemia, antiarrhythmic proarrhythmia, myocardial ischemia).
Phrenic nerve stimulation (PNS), occurring in 33%-37% of the patients with cardiac resynchronization therapy (CRT), is a limiting factor when implanting left ventricular (LV) leads from coronary ...veins.
To test the hypothesis that PNS occurrence is related to bipolar electrode spacing.
During standard CRT defibrillator implant procedures, a 5-F diagnostic electrophysiology catheter with 10 electrodes, spaced 2-5-2 mm, was positioned in a cardiac vein suitable for permanent LV lead placement. Pacing in the unipolar configuration identified the site with the lowest PNS threshold. PNS and left ventricular pacing (LVP) thresholds were then measured in different configurations at 0.5 ms: unipolar, each LV electrode served as the cathode in turn; and bipolar with different electrode spacing, cathode being the electrode with the lowest unipolar PNS threshold.
From February to September 2010, 40 patients undergoing CRT implantation were enrolled in 4 centers in Italy. It was possible to identify PNS and perform a complete set of measurements in 23 patients. A bipolar electrode spacing of 2 mm resulted in higher PNS thresholds in bipolar configurations han did a bipolar electrode spacing of ≥ 5 mm. However, no significant increase in the LVP threshold was observed (P = ns).
This experience suggests that LVP with a bipolar electrode spacing of 2 mm significantly increases the PNS threshold without affecting the LVP threshold, thereby increasing the possibility of delivering CRT when the LV lead is placed in proximity to the phrenic nerve.
Intraventricular Delay and Blocks Leonelli, Fabio M; Bagliani, Giuseppe; De Ponti, Roberto ...
Cardiac electrophysiology clinics,
06/2018, Letnik:
10, Številka:
2
Journal Article
Recenzirano
From the atrioventricular node, electrical activation is propagated to both ventricles by a system of specialized conducting fibers, His Purkinje System (HPS), guaranteeing a fast, synchronous ...depolarization of both ventricles. From the predivisional common stem, a right and left branch separate, subdividing further in a fairly predictable fashion. Synchronous ventricular activation results in a QRS with specific characteristics and duration of less than 110 milliseconds. Block or delay in any part of the HPS changes the electrocardiographic (ECG) morphology. This article discusses the use and limitations of standard ECG in detecting abnormal ventricular propagation in specific areas of the HPS.
Abstract Background Novel facilities such as an intensive observation unit and an outpatient clinic could result in improving management of patients presenting with atrial fibrillation (AF). Methods ...This observational study enrolled 3475 patients. Group 1 (1120 patients; years 2004-2005) was managed with standard approach; group 2 (992 patients; years 2006-2007) was managed with additional intensive observation; group 3 (1363 patients; years 2008-2009) was managed with additional intensive observation and outpatient clinic. Primary end point was admission to hospital. Secondary end points included modalities of rhythm conversion and administration of class IC vs class III antiarrhythmic drugs in patients with AF lasting less than 48 hours. Results Lack of rhythm control, comorbidities, diabetes, and age were independent predictors of hospitalization. Admissions significantly decreased from group 1 (50%) to 2 (38%) and to 3 (24%) ( P < .001). Interestingly, more than a quarter of patients in group 3 were referred to the outpatient clinic for short-term follow-up, eventually avoiding admission. Patients with AF lasting less than 48 hours (n = 2189) and without structural heart disease (n = 1685) achieved sinus rhythm in 89% of cases and were discharged. In these patients, early administration of antiarrhythmic drugs of class IC and III gained sinus rhythm in 80% and 20%, respectively ( P < .001). Spontaneous conversion occurred in 26%; electrical, 17%; and pharmacological, 57%. Conclusions In patients with AF, beyond the standard approach, the novel organization with an additional intensive observation unit for early pharmacological interventions and an outpatient clinic for elective treatment and short-term follow-up significantly reduced admission irrespective of independent predictors of hospitalizations. Patients without structural heart disease treated with antiarrhythmic drugs achieved sinus rhythm in 89% of cases, mostly with class IC drugs.
During radiofrequency ablation, effective contact is crucial in determining lesions efficacy.
The purpose of this study was to compare operators' ability to assess contact pressure using visual and ...tactile feedbacks together or alone in an experimental model.
In a in vitro experimental setup replicating manual catheter manipulation and recording the applied force, evaluators were asked to identify three levels of force (first, ablation, and maximum contact) as the catheter contacted the tissue model using (1) visual feedback only by fluoroscopy, "blinded" to touch; (2) tactile feedback only, blinded to fluoroscopy; and (3) both tactile and visual feedback together. The latter was regarded as reference. The experiment was repeated using a catheter force sensing technology during robotic navigation.
During manual navigation, tighter association was shown for the visual method than for the tactile method: median difference with reference: first contact -1 (P = .97) vs -2 (P = .90); ablation contact 2 (P = .1) vs -7 (P = .03); maximum contact 2 (P = .06) vs -28 (P = .02). Bland-Altman plot and Deming regression confirmed for the visual method the good agreement with reference and the absence of bias at any level and showed for the tactile higher values and proportional bias that reached statistical significance at ablation and maximum contact. During robotic navigation, agreement was higher for the tactile than for the visual only method.
During manual navigation, visual feedback alone is in better agreement with the reference compared to the tactile only approach. During robotic navigation, agreement is looser for the visual only approach. More objective feedback of contact pressure during ablation procedures is desirable.
Abstract Background The link between minor troponin (cardiac troponin I cTnI) elevations and atrial fibrillation (AF) is still debated. Methods A total of 948 patients with AF lasting less than 48 ...hours participated in the study and were required to undergo 1-month and 12-month follow-up. The exclusion criteria were represented by younger than 18 years, the presence of hemodynamic instability, or severe comorbidity. Primary end point was the composite of ischemic vascular events inclusive of stroke, acute coronary syndrome, revascularization, and death. Results In the short term, 4 patients (5%) of 78 with abnormal cTnI reached the primary end point ( P = .001 vs others). Conversely, in the long term, 13 patients (17%) with abnormal cTnI, 21 (10%) with known ischemic vascular disease, and 50 (5%) aged patients (75 ± 10 years) reached the primary end point ( P < .001, P < .001, and P = .002, respectively). At multivariate analysis, abnormal cTnI (hazard ratio HR, 2.84; 95% confidence interval, 1.38-5.84; P = .005), known ischemic vascular disease (HR, 2.03; 95% confidence interval, 1.11-3.70; P = .021), and age (HR, 1.05; 95 confidence interval, 1.02-1.08; P = .002) were predictors of the primary end point. Minimal or minor cTnI elevation (< 0.45 or ≥ 0.45 ng/mL, respectively) showed no differences when associated with the primary end point. The C-statistic demonstrated the significant prognostic value of older age and known ischemic vascular disease, beyond troponin. Clinical parameters inclusive of heart rate, blood pressure, and risk factors for arteriosclerosis showed no relationship with adverse events. Readmission rate did not differ between groups. Conclusions In patients with acute AF, minor cTnI elevations link to short-term adverse events. Known ischemic vascular disease and older age showed prognostic value only in the long term.
Simultaneous stimulation of 2 left ventricular (LV) sites could enhance the effectiveness of cardiac resynchronization therapy (CRT). The aim of this study was to evaluate the acute hemodynamic ...response to dual-site LV CRT. Two LV pacing leads were successfully implanted in 12 CRT candidates (New York Heart Association classes III to IV, QRS ≥120 ms). Target positions were the lateral or posterolateral vein (site A) and anterior or anterolateral vein (site B). A conductance catheter was placed in the left ventricle for pressure–volume measurements. Tested CRT configurations were alternated by atrial overdrive pacing at a fixed rate and included site A and B single-site CRT and dual-site LV CRT (2 LV sites plus right ventricular apex) at 4 atrioventricular intervals. Overall, single-site LV CRT significantly enhanced stroke volume, stroke work, maximum pressure derivative, and conductance-derived indexes of LV synchrony when delivered in site A, whereas no significant changes were noticed with pacing in site B. Specifically, site-A pacing resulted in a higher stroke volume increase (LV pacing site associated with the best hemodynamic response best-LV) in 8 patients, and site-B pacing, in 4 patients. At intermediate atrioventricular intervals, dual-site LV CRT resulted in improved stroke volume, stroke work, maximum pressure derivative, and LV synchrony with respect to single-site CRT when delivered at the best-LV (all p <0.05). However, single-site CRT at best-LV produced results similar to dual-site LV CRT when the atrioventricular interval was optimized in each patient. In conclusion, adding a second LV lead does not result in further improvement in acute hemodynamic response with respect to standard CRT when the single LV pacing site and atrioventricular interval are optimal.
Introduction The experimental concept that “atrial fibrillation (AF) begets AF” implies that atrial tachyarrhythmia (AT)/AF burden uniformly increases over time. However, the temporal patterns of ...paroxysmal AT/AF burden progression, its conversion to persistent AF, and the relationship to underlying disease in humans are unknown. We analyzed the average daily AT/AF burden in patients with concomitant bradycardia and paroxysmal AF to examine these issues. Methods Three hundred thirty patients with a history of paroxysmal AF (mean age 70 ± 10 years; 61% male) were implanted with a pacemaker that automatically recorded the cumulative daily AT/AF burden. Persistent AT/AF was defined as 7 consecutive days with >23 hours of AT on the device data logs. Antiarrhythmic drug therapy was required to be stable for at least 7 months. Results Average follow-up was 401 ± 123 days. Seventy-eight patients (24%) progressed to persistent AT/AF during the follow-up period with a mean interval of 147 ± 149 days. Mean AT/AF burden increased progressively (slope 14 s/d, P < .001) over 500 days after implant, and median AT/AF burden also increased ( P < .01) in this subgroup of patients. This increase was highly correlated with the presence of structural heart disease ( P < .001). There was a concomitant decrease in atrial premature beat (APB) frequency. Most patients transitioning to persistent AF were in sinus rhythm with minimal AT/AF burden in the days immediately before persistent AF. Neither mean nor median AT/AF burden increased over time in patients remaining in paroxysmal AF (slope 0 s/d, P = .7) despite a higher APB frequency than in patients with heart disease ( P =.003) and a higher likelihood of daily AT/AF events ( P < .001). Conclusions Temporal patterns of AT/AF burden in patients developing persistent AF show a progressive increase with a sudden transition to persistent AF. This is more consistent with substrate changes, rather than increased density of triggering APBs or paroxysmal AT/AF events. Thus, progression to persistent AF is probably related to an AF substrate, which is undergoing progressive structural remodeling owing to heart disease and other factors and is now suddenly capable of sustaining prolonged or multiple ATs. Therapies directed at the atrial substrate may be needed to prevent persistent AF.
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