M.M.M. Cortês

Silent ischaemic brain lesions related to atrial high rate episodes in patients with cardiac implantable electronic devices

AIMS Monitoring capabilities of cardiac implantable electronic devices have revealed that a large proportion of patients present silent atrial fibrillation (AF) detected as atrial high rate episodes (AHREs). Atrial high rate episodes >5 min have been linked to increased risk of clinical stroke, but a high proportion of ischaemic brain lesions (IBLs) could be subclinical. METHODS AND RESULTS We prospectively analysed the incidence of AHRE > 5 min in 109 patients (56% men, aged 74 ± 9 years) and the presence of silent IBL on computed tomography (CT) scan. Mean CHADS2 and CHA2DS2VASc scores were 2.3 ± 1.3 and 3.9 ± 1.6, respectively. Seventy-five patients (69%) had no history of AF or stroke/transient ischaemic attack (TIA). After 12 months, 28 patients (25.7%) showed at least one AHRE. Patients with AHREs were more likely to have history of AF. Computed tomography scan showed silent IBL in 28 (25.7%). The presence of IBL was significantly related to older patients, prior history of AF or stroke/TIA, higher CHADS2 or CHA2DS2VASc scores, and the presence of AHRE. Multivariable analysis demonstrated that AHRE was an independent predictor for silent IBL in overall population [hazard ratio (HR) 3.05 (1.06-8.81; P < 0.05)] but also in patients without prior history of AF or stroke/TIA [HR 9.76 (1.76-54.07; P < 0.05)]. CONCLUSION Cardiac implantable electronic devices can accurately detect AF as AHRE. Atrial high rate episodes were associated to a higher incidence of silent IBL on CT scan. Atrial high rate episodes represent a kind of silent AF where management recommendations are lacking despite the fact that a higher embolic risk is present.

Silent brain infarcts in high blood pressure patients with cardiac implantable electronic devices: unmasking silent atrial fibrillation.

Background: Hypertensive patients present a higher risk for developing atrial fibrillation and its complications. Cardiac implantable electronic devices (CIEDs) have shown reliable atrial fibrillation detection as atrial high-rate episodes (AHREs). The presence of AHRE more than 5 min has been related to increased risk of stroke, but a high proportion of ischemic brain lesions (IBLs) could be subclinical and thromboembolic risk underestimated. Methods: We included hypertensive patients with CIED and we analyzed the incidence of AHRE and the presence of IBL on computed tomography (CT) scan. Results: One hundred and twenty-three patients (57% men) aged 77 ± 8 years were evaluated during a mean follow-up of 15 ± 9 months. AHREs were documented in 46 patients (37%). Cranial CT scan showed silent IBL in 34 patients (27%). Univariate analysis showed that age, CHADS2 and CHADS2VA2Sc scores, history of prior stroke/ transient ischemic attack and the presence of AHRE were significantly related to higher risk for IBL on CT scan (P < 0.05). Multivariate analysis showed that the presence of AHRE more than 5 min [odds ratio 3.05 (1.19–7.81; P < 0.05)] was an independent predictor of IBL. Conclusion: Silent atrial fibrillation detected by CIED as AHRE is really prevalent in hypertensive patients. AHREs were independently associated with a higher incidence of silent IBL on CT scan.

Limitations of the AutoCapture™ Pacing System in patients with cardiac stimulation devices

AIMS AutoCapture (St Jude Medical) is a technological development that confirms ventricular capture analysing the evoked response after a pacing impulse and adjusts the energy output to changes in the stimulation threshold. Although this algorithm is aimed to assure capture minimizing energy consumption, some patients might not benefit from it. The objective of this study is to identify them. METHODS AND RESULTS Long-term AutoCapture efficiency was assessed using the data recorded in the programmer reports of patients undergoing scheduled pacemaker check-ups during 2012 in our institution. We have evaluated 160 consecutive patients (58% men) aged 78 ± 9 years. Pacemaker stimulation mode was DDD in 116 patients (72.5%) and VVI in 44 patients (27.5%). During the scheduled visits for pacemaker check-up, 73 patients (45.6%) showed abnormalities in the long-term AutoCapture function report (high variability in the AutoCapture stimulation threshold and/or out-of-range values). After multivariate analysis, abnormal AutoCapture pattern was associated to the presence of atrial fibrillation [odds ratio (OR) 3.96 (1.59-9.82; P < 0.05)]; and a ventricular pacing ≤25% of the time [OR 4.80 (2.09-11.05; P < 0.05)]. AutoCapture abnormalities were also described in three (1.8%) patients with very low stimulation threshold. CONCLUSION Although AutoCapture algorithm has shown both efficacy and safety, our findings suggest that some patients with atrial fibrillation or those requiring ventricular pacing ≤25% of the time may not benefit from it. Activation of the algorithm should be individualized according to the patients characteristics and long-term AutoCapture pattern checked in the routine follow-up.

Seventy-six-year-old man with progressive dyspnoea

Clinical introduction A 76-year-old man with 50 years of smoking history was diagnosed in 2012 with diffuse interstitial lung disease, with radiological data of usual interstitial pneumonia. He came to the emergency room presenting with progression of dyspnoea for 1 week, concomitant with loss of 5 kg of weight, anorexia and poor general condition. He had tachypnoea at rest (30 breaths/min), peripheral cyanosis, speech interfered by cough and breathlessness, baseline oxygen saturation 90%, heart rate 40 beats/min and blood pressure 130/70 mm Hg. Chest X-ray was performed and there was basal atelectasia of the right lung. ECG and urgent echocardiogram (transthoracic echocardiogram, TTE) were also performed (figure 1). Question Which of the following best explains the patient’s situation?Figure 1 (A) ECG. (B) Long-axis parasternal view from the transthoracic echocardiogram (TTE)

Silent atrial fibrillation in pacemaker early post-implantation period: an unintentionally provoked situation?

Aims Atrial high-rate episodes (AHREs) compatible with silent AF detected in pacemakers (PM) are related to an increased risk of stroke and silent ischaemic brain lesions (IBL) on CT scan. AHREs soon after PM implantation could be related with the procedure itself and the prognosis might be different. Methods and results We analysed the incidence of AHREs >5 min and the presence of silent IBL in 110 patients (56% men, aged 75 ± 9 year-old) with PM and no history of AF, in relation to time from implantation (≤3 months vs. >3 months) and the atrial lead fixation (LF) (active vs. passive). Mean CHADS2 and CHA2DS2VASc scores were 1.9 ± 1.2 and 3.5 ± 1.5, respectively. Time from implantation was ≤3 months in 88 patients (80%). Active LF was used in 55 patients (50%). After 24 ± 9 months, AHREs were present in 40 patients (36.4%). CT-scan showed silent IBL in 26 patients (23.6%). The presence of AHREs at 3 months was more frequent in the patients with recent PM implantation (17% vs. 4.5%, P = 0.09) and significantly related to active LF (OR 5.36, 1.43-20.07; P < 0.05). The presence of silent IBL was related to the detection of AHREs during follow up (OR 3.12, 1.29-7.97; P < 0.05) but not with AHREs at first 3 months (OR 1.58, 0.49-5.05; P = 0.44). Conclusions AHREs occur frequently during the first 3 months after PM implantation and could be related with procedure itself and the use of active LF. AHREs in this period might not be related to worse outcomes and should be interpreted cautiously.

Comparison of pharmacological treatment alone vs. treatment combined with implantable cardioverter defibrillator therapy in patients older than 75 years: Pharmacological treatment alone vs. treatment with ICD therapy

Implantable cardioverter defibrillator (ICD) reduces mortality in selected patients. However, its role in patients older than 75 years is not well established.

ATRIAL HIGH RATE EPISODES AND SILENT ISCHEMIC BRAIN LESIONS IN PATIENTS WITH CARDIAC IMPLANTABLE ELECTRONIC DEVICES: UNMASKING SILENT ATRIAL FIBRILLATION EMBOLIC RISK

Cardiac implantable electronic devices (CIED) reveal that many patients present silent atrial fibrillation (AF) detected as atrial high rate episodes (AHRE). AHRE >5min have been linked to increased risk of clinical stroke, but a high proportion of ischemic brain lesions (IBL) could be subclinical

COMPARISON OF OPTIMAL PHARMACOLOGICAL TREATMENT ALONE AND COMBINED WITH CARDIAC RESYNCHRONIZATION THERAPY IN PATIENTS OVER 75 YEARS

Cardiac Resynchronization Therapy (CRT) in patients with heart failure (HF) and a widened QRS complex improves clinical outcomes and reduces mortality in selected patients. Its role in patients aged ≥75 years, is not well established. From January 2008 to April 2012 we have recruited