Ambulatory respiratory rate trends identify patients at higher risk of worsening heart failure in implantable cardioverter defibrillator and biventricular device recipients: a novel ambulatory parameter to optimize heart failure management.

PURPOSE: Respiratory distress is the primary driver for heart failure (HF) hospitalization. Implantable pacemakers and defibrillators are capable of monitoring respiratory rate (RR) in ambulatory HF patients. We investigated changes in RR prior to HF hospitalizations and its near-term risk stratification power. METHODS: NOTICE-HF was an international multi-center study. Patients were implanted with an implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, capable of trending daily maximum, median, and minimum RR (maxRR, medRR, minRR). RR from 120 patients with 9 months of follow-up was analyzed. One-tailed Student's t test was used to compare RR values prior to HF events to baseline defined as 4 weeks prior to the events. A Cox regression model was used to calculate the hazard ratios (HR) for the 30-day HF hospitalization risk based on RR values in the preceding month. RESULTS: Daily maxRR, medRR, and minRR were significantly elevated prior to HF events compared to baseline (ΔmaxRR 1.8 ± 3.0; p = 0.02; ΔmedRR, 2.1 ± 2.8; p = 0.007; ΔminRR, 1.5 ± 2.1, p = 0.008). Risk of experiencing HF events within 30-days was increased if the standard deviation of medRR over the preceding month was above 1.0 br/min (HR = 12.3, 95 % confidence interval (CI) 2.57-59, p = 0.002). The risk remained high after adjusting for clinical variables that differed at enrollment. CONCLUSION: Ambulatory daily respiratory rate trends may be a valuable addition to standard management for HF patients.

Optimizing radiofrequency ablation of paroxysmal and persistent atrial fibrillation by direct catheter force measurement-a case-matched comparison in 198 patients.

BACKGROUND: Sufficient electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). OBJECTIVE: We assessed the impact of direct catheter force measurement on acute procedural parameters and outcome of RFCA for paroxysmal and persistent atrial fibrillation (AF). METHODS: Ninety-nine consecutive patients (70% men) with paroxysmal (63.6%) or persistent AF underwent left atrial RFCA using a 3.5-mm open-irrigated-tip (OIT) catheter with contact force measurement capabilities (group 1). For comparison a case-matched cohort with standard OIT catheters was used (99 patients; group 2). Case matching included gender, type of AF, number or RFCA procedures, and type of procedure. RESULTS: Procedural data showed a significant decline in radiofrequency ablation time from 52 ± 20 to 44 ± 16 minutes (P = 0.003) with a remarkable mean reduction in overall procedure time of 34 minutes (P = 0.0001; 225.8 ± 53.1 vs 191.9 ± 53.3 minutes). In parallel, the total fluoroscopy time could be significantly reduced from 28.5 ± 11.0 to 19.9 ± 9.3 minutes (P = 0.0001) as well as fluoroscopy dose from 74.1 ± 58.0 to 56.7 ± 38.9 Gy/cm(2) (P = 0.016). Periprocedural complications were similar in both groups. CONCLUSIONS: The use of contact force sensing technology is able to significantly reduce ablation, procedure, and fluoroscopy times as well as dose in RFCA of AF in a mixed case-matched group of paroxysmal and persistent AF. Energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Additionally 12-month outcome data showed increased efficacy. Such time saving and equally safe technology may have a relevant impact on laboratory management and increased cost effectiveness.

Asymptomatic cerebral lesions during pulmonary vein isolation under uninterrupted oral anticoagulation.

AIMS: Left atrial radiofrequency ablation has been shown to carry a risk of asymptomatic cerebral lesions. No data exist in patients under continued oral anticoagulation during the ablation procedure. The aim of this study was to quantify the amount of silent cerebral lesions assessed by pre-procedural and post-procedural magnetic resonance imaging (MRI) in patients under therapeutic international normalized ratio (INR) and to identify clinical or procedural parameters that correlate with cerebral embolism. METHODS AND RESULTS: A total of 131 consecutive patients undergoing catheter ablation for paroxysmal (n = 80, 61.1%) or persistent (n = 51, 38.9%) atrial fibrillation were included in the study. Pulmonary vein antrum isolation (PVI), roofline, mitral isthmus line, and complex fractionated atrial electrogram (CFAE) ablation using 3.5 mm open-irrigated tip catheters were performed, as needed. All patients underwent pre-procedural and post-procedural cerebral MRI. Post-procedural MRI revealed new embolic lesions in 16 patients (12.2%), all of them asymptomatic. Clinical parameters showing a significant correlation with cerebral embolism in univariate analysis were age (P = 0.027), persistent atrial fibrillation (vs. paroxysmal; P = 0.039), and spontaneous echo contrast in transesophageal echocardiography (P = 0.029). Significant procedural parameters were electric cardioversion (P = 0.041), PVI only (P = 0.008), and ablation of complex atrial electrograms (P = 0.005). Independent risk factors in multivariate analysis were age (P = 0.009), spontaneous echo contrast (P = 0.029) and CFAE ablation (P = 0.006). CONCLUSION: Radiofrequency ablation in patients under continued oral therapeutic anticoagulation is associated with a substantial risk of silent embolism detected by cerebral MRI. Therefore, continuation of oral anticoagulation is not able to prevent cerebral embolism. A variety of different clinical and procedural factors seem to contribute to the risk of cerebral lesions.

Clinical impact of an open-irrigated radiofrequency catheter with direct force measurement on atrial fibrillation ablation.

BACKGROUND: Electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). OBJECTIVE: We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). METHODS: Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.5-mm open-irrigated-tip catheter or (2) a catheter with contact force measurement capabilities. Using the endpoint of PVI with entry and exit block, acute procedural parameters were assessed. RESULTS: Procedural data showed a remarkable decline in ablation time (radiofrequency time needed for PVI) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes (P = 0.007) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes (P = 0.022). In parallel, the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws (P = 0.019). The number of acute PV reconnections declined from 36% to 12% (P = 0.095). CONCLUSIONS: The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI. In addition, energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts.

Cardiac resynchronization therapy by ablation of right-anterolateral accessory pathway.

Ventricular preexcitation caused by right-sided accessory pathways can lead to abnormal septal motion patterns and may be associated with left ventricular (LV) dysfunction and heart failure, despite the lack of a clinical arrhythmia. Hence successful ablation of the accessory pathway abolishes not only preexcitation but also ventricular dyssynchrony in these patients. We describe a case of an asymptomatic 20-year-old male presenting with ventricular Type-B preexcitation combined with LV dysfunction. The individual risk of arrhythmic events was enhanced due to competitive sport activities of the patient and a short antegrade refractory period of the accessory pathway. Hence standard radiofrequency ablation of the right anterolateral accessory pathway was performed, despite no history of tachycardia. After successful accessory pathway ablation, normalization of LV size and function was demonstrated by echocardiography with a long-term follow-up of 4 years.

[Endo- and epicardial catheter ablation preventing ventricular tachycardia: impact of substrate modification]. / Endo- und epikardiale katheterablation in der behandlung ventrikulärer tachykardien: bedeutung der substratmodifikation.

Challenges encountered during catheter ablation of ventricular tachycardia (VT) include hemodynamic instability and lack of inducibility. Recent approaches guided by electroanatomic mapping demonstrated the feasibility of VT ablation during sinus rhythm. We analyzed the data from 40 consecutive patients who were referred to the Elisabethinen Hospital Linz for VT ablation. Ablation target sites were identified by using pace-, electroanatomic, and specific VT-related potential mapping. All clinical VTs were eliminated by catheter ablation in 38 of 40 patients within 43 procedures. Epicardial mapping and ablation via a subxiphoid percutaneous access was necessary in 3 patients. In total, 4 out of 14 patients with a history of frequent ICD shocks received additional ICD discharges during follow-up (n = 2:ICD-shock; n = 2:antitachycardia-pacing). Combining pace-, activation-, entrainment-, and substrate-mapping is useful for VT prevention by catheter ablation. A subxiphoid percutaneous approach is useful in some patients for extensive mapping and ablation at the epicardial surface of the heart.

Dyssynchrony by speckle-tracking echocardiography and response to cardiac resynchronization therapy: results of the Speckle Tracking and Resynchronization (STAR) study.

AIMS: The Speckle Tracking and Resynchronization (STAR) study used a prospective multi-centre design to test the hypothesis that speckle-tracking echocardiography can predict response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS: We studied 132 consecutive CRT patients with class III and IV heart failure, ejection fraction (EF) < or =35%, and QRS > or =120 ms from three international centres. Baseline dyssynchrony was evaluated by four speckle tracking strain methods; radial, circumferential, transverse, and longitudinal (> or =130 ms opposing wall delay for each). Pre-specified outcome variables were EF response and three serious long-term events: death, transplant, or left ventricular assist device. Of 120 patients (91%) with baseline dyssynchrony data, both short-axis radial strain and transverse strain from apical views were associated with favourable EF response 7 +/- 4 months and long-term outcome over 3.5 years (P < 0.01). Radial strain had the highest sensitivity at 86% for predicting EF response with a specificity of 67%. Serious long-term unfavourable events occurred in 20 patients after CRT, and happened three times more frequently in those who lacked baseline radial or transverse dyssynchrony than in patients with dyssynchrony (P < 0.01). Patients who lacked both radial and transverse dyssynchrony had unfavourable clinical events occur in 53%, in contrast to events occurring in 12% if baseline dyssynchrony was present (P < 0.01). Circumferential and longitudinal strains predicted response when dyssynchrony was detected, but failed to identify dyssynchrony in one-third of patients who responded to CRT. CONCLUSION: Dyssynchrony by speckle-tracking echocardiography using radial and transverse strains is associated with EF response and long-term outcome following CRT.

Speckle tracking in the evaluation of left ventricular dyssynchrony.

A number of echocardiographic techniques have been introduced to determine left ventricular dyssynchrony (LVD) and to improve selection of patients for CRT. During the last years tissue Doppler imaging (TDI) has been used as the most preferred technique to quantify LVD, but results with nonresponder rates below 30% have been shown only in small studies based on high experience. Angle of incidence dependency, noise, artifacts, and tethering motion of adjacent segments are the main limitations of TDI influencing selection of patients for CRT. Although strain TDI is not affected by translation or tethering, accurate measurement of regional strain is also limited. Two-dimensional (2D) strain imaging based on novel speckle tracking echocardiography (STE) is a relatively new tool to define regional myocardial strain and to quantify dyssynchrony based on a more robust technique and avoiding angle of incidence. Current studies are promising to use strain or vector velocity imaging derived from STE for qualitative and quantitative assessment of LVD and follow-up studies as well. If one compare different types of strain components at present, radial strain imaging seems to be the most promising technique to determine LVD and to predict positive response to CRT. Furthermore, STE offers an insight into rotational mechanics of the dyssynchronous ventricle. Although clinical studies using 2D strain have analyzed LVD related to various conditions, measures are based on a 2D data set. Three-dimensional strain imaging, based on speckle tracking will probably open a new door to assess patients with heart failure and LVD.

Echocardiographic aspects of multisite pacing in patients undergoing cardiac resynchronization therapy.

BACKGROUND: Echocardiography has emerged as an accepted approach to define dyssynchrony in patients with advanced stage of heart failure (HF). Unfortunately no single echocardiographic parameter has been established to predict positive response after cardiac resynchronization therapy (CRT) and the nonresponder rate of 20-30% is still a matter of discussion and research. One of the most promising techniques in this regard is two-dimensional strain echocardiography based on speckle tracking with the potential to disclose residual dyssynchrony after primary CRT. An important reason for weak response to CRT is suboptimal position of the coronary sinus (CS) lead. Initial clinical benefit after CRT may mask partial residual dyssynchrony, which may cause worsening and recurrence of HF symptoms over time. Echocardiography helps to define the location of residual dyssynchrony and may identify patients who would benefit from implantation of a second CS-lead and triple-site pacing. If primary CRT fails due to imperfect placement of the CS-lead or due to coronary vein abnormalities and an epicardial approach is not appropriate, dual site pacing of the right ventricle may be an alternative procedure.

GOLDART--Gold Alloy Versus Platinum-Iridium Electrode for Ablation of AVNRT.

INTRODUCTION: Radiofrequency (RF) catheter ablation targeting the slow pathway is currently the most effective treatment for patients with atrioventricular nodal reciprocating tachycardia (AVNRT). Gold exhibits a more than four times greater thermal conductivity than platinum, and the creation of deeper lesions was demonstrated in ex vivo animal experiments. The current clinical trial was initiated to compare gold catheters with standard platinum-iridium (Pt-Ir) material and to analyze differences in the increase of power or temperature as a function of time during RF ablation. METHODS: A prospective, randomized multicenter study design was used to compare RF deliveries at the slow pathway with standard Pt-Ir tip catheters (128 patients), as well as gold alloy tip electrodes (124 patients) during AVNRT ablation. RESULTS: Although there was a trend towards higher power delivery in the gold group (4.96 vs. 4.28 W/s), this trend was not statistically significant. Likewise, cumulative duration of all RF ablations, total procedure time, and power delivered at other time points were not significantly different between the groups. Also, the occurrence of AV-block and sensations of pain were similar in both treatment groups. However, charring on the catheter tip after the intervention was observed eightfold more frequently in the Pt-Ir group. CONCLUSION: In conclusion, power delivery cannot be significantly increased by RF ablation of AVNRT with gold electrodes. But the electrode material seems to be safe and well-tolerated and specifically did not increase the risk of AV-block. The significant reduction of coagulum formation on gold tips suggests a possible advantage of this material beyond its better conduction properties.

Right ventricular metastasis of uterine squamous cell carcinoma.

This imaging case report demonstrates abnormal right ventricular masses of primarily unknown origin. The woman was admitted because of right heart failure symptoms. Echocardiography showed the masses exclusively related to the right ventricular endomyocardium and extending through the entire length and breadth of the ventricle. Systolic function was normal without evidence of outflow tract obstruction. The patient died in 3 days because of multisystem failure. Autopsy findings confirmed metastasis on the right ventricle and histopathology demonstrated the infrequent finding of metastasis from uterine squamous cell carcinoma, which had been operated on 5 years before.