Diagnostic yield of implantable loop recorders: Results from the Hellenic registry.

AIMS: Implantable loop recorders (ILRs) are increasingly being used for long-term cardiac monitoring in different clinical settings. The aim of this study was to investigate the real-world performance of ILRs-including the time to diagnosis- in unselected patients with different ILR indications. METHODS AND RESULTS: In this multicenter, observational study, 871 patients with an indication of pre-syncope/syncope (61.9%), unexplained palpitations (10.4%), and atrial fibrillation (AF) detection with a history of cryptogenic stroke (CS) (27.7%) underwent ILR implantation. The median follow-up was 28.8 ± 12.9 months. In the presyncope/syncope group, 167 (31%) received a diagnosis established by the device. Kaplan-Meier estimates indicated that 16.9% of patients had a diagnosis at 6 months, and the proportion increased to 22.5% at 1 year. Of 91 patients with palpitations, 20 (22%) received a diagnosis based on the device. The diagnosis established at 12.2% of patients at 6 months, and the proportion increased to 13.3% at 1 year. Among 241 patients with CS, 47 (19.5%) were diagnosed with AF. The diagnostic yield of the device was 10.4% at 6 months and 12.4% at 1 year. In all cases, oral anticoagulation was initiated. Overall, ILR diagnosis altered the therapeutic strategy in 26.1% in presyncope/syncope group, 2.2% in palpitations group, and 3.7% in CS group in addition to oral anticoagulation initiation. CONCLUSIONS: In this real-world patient population, ILR determines diagnosis and initiates a new therapeutic management in nearly one fourth of patients. ILR implantation is valuable in the evaluation of patients with unexplained presyncope/syncope, CS and palpitations.

Diagnostic and therapeutic dilemmas in a patient with myocarditis, Brugada syndrome and arrhythmic syncope.

We present a case of a previously healthy 23-year-old male who presented with chest pain, palpitations and spontaneous type 1 Brugada electrocardiographic (ECG) pattern. Positive family history for sudden cardiac death (SCD) was remarkable. Initially, clinical symptoms in combination with myocardial enzymes elevation, regional myocardial oedema with late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and inflammatory lymphocytoid-cell infiltrates in the endomyocardial biopsy (EMB) suggested the diagnosis of a myocarditis-induced Brugada phenocopy (BrP). Under immunosuppressive therapy with methylprednisolone and azathioprine, a complete remission of both symptoms and biomarkers was accomplished. However, the Brugada pattern did not resolve. The eventually spontaneous Brugada pattern type 1 established the diagnosis of Brugada syndrome (BrS). Due to his previous history of syncope, the patient was offered an ICD that he declined. After his discharge he experienced a new episode of arrhythmic syncope. He was readmitted and received an ICD.

Ventricular Tachycardia Has Mainly Non-Ischaemic Substrates in Patients with Autoimmune Rheumatic Diseases and a Preserved Ejection Fraction.

Non-sustained ventricular tachycardia (NSVT) is a potentially lethal arrhythmia that is most commonly attributed to coronary artery disease. We hypothesised that among patients with NSVT and preserved ejection fraction, cardiovascular magnetic resonance (CMR) would identify a different proportion of ischaemic/non-ischaemic arrhythmogenic substrates in those with and without autoimmune rheumatic diseases (ARDs). In total, 80 consecutive patients (40 with ARDs, 40 with non-ARD-related cardiac pathology) with NSVT in the past 15 days and preserved left ventricular ejection fraction were examined using a 1.5-T system. Evaluated parameters included biventricular volumes/ejection fractions, T2 signal ratio, early/late gadolinium enhancement (EGE/LGE), T1 and T2 mapping and extracellular volume fraction (ECV). Mean age did not differ across groups, but patients with ARDs were more often women (32 (80%) vs. 15 (38%), p < 0.001). Biventricular systolic function, T2 signal ratio and EGE and LGE extent did not differ significantly between groups. Patients with ARDs had significantly higher median native T1 mapping (1078.5 (1049.0-1149.0) vs. 1041.5 (1014.0-1079.5), p = 0.003), higher ECV (31.0 (29.0-32.0) vs. 28.0 (26.5-30.0), p = 0.003) and higher T2 mapping (57.5 (54.0-61.0) vs. 52.0 (48.0-55.5), p = 0.001). In patients with ARDs, the distribution of cardiac fibrosis followed a predominantly non-ischaemic pattern, with ischaemic patterns being more common in those without ARDs (p < 0.001). After accounting for age and cardiovascular comorbidities, most findings remained unaffected, while only tissue characterisation indices remained significant after additionally correcting for sex. Patients with ARDs had a predominantly non-ischaemic myocardial scar pattern and showed evidence of diffuse inflammatory/ischaemic changes (elevated native T1-/T2-mapping and ECV values) independent of confounding factors.

Cardiovascular magnetic resonance imaging pattern in patients with autoimmune rheumatic diseases and ventricular tachycardia with preserved ejection fraction.

BACKGROUND: Ventricular tachycardia/fibrillation (VT/VF) may occur in autoimmune rheumatic diseases (ARDs). We hypothesized that cardiovascular magnetic resonance (CMR) can identify arrhythmogenic substrates in ARD patients. PATIENTS - METHODS: Using a 1.5 T system, we evaluated 61 consecutive patients with various types of ARDs and normal left ventricular ejection fraction (LVEF) on echocardiography. A comparison of patients with recent VT/VF and those that never experienced VT/VF was performed. CMR parameters included left and right ventricular (LV and RV) end-systolic and end-diastolic volumes (ESV and EDV), T2 signal ratio of myocardium over skeletal muscle, early/late gadolinium enhancement (EGE and LGE), T1/T2-mapping and extracellular volume fraction (ECV). RESULTS: 21 (34%) patients had a history of recent, electrocardiographically identified, VT/VF. No demographic or functional CMR variables differed significantly between groups. The same was the case for T2 signal ratio and EGE/LGE. Median native T1 mapping values were significantly higher in patients with VT/VF compared to those without [1135.0 (1076.0, 1201.0) vs. 1050.0 (1025.0, 1078.0), p < 0.001], as was the case for mean T2 mapping [60.4 (6.6) vs. 55.0 (7.9), p = 0.009] and median ECV values [32.0 (30.0, 32.0) vs. 29.0 (28.0, 31.5), p = 0.001]. After multivariate corrections for age, LVEDV, LVEF, RVEDV, RVEF, T2 signal ratio, EGE and LGE, these remained significant predictors of having experienced VT/VF in the past. CONCLUSIONS: T1/T2-mapping and ECV offer incremental value as identifiers of arrhythmogenic substrates in ARD patients, beyond traditionally used indices. They can thus guide implantable cardiac defibrillator (ICD) implantation in ARD patients presenting with VT/VF and normal LVEF.

Prospects of using cardiovascular magnetic resonance in the identification of arrhythmogenic substrate in autoimmune rheumatic diseases.

Sudden cardiac death (SCD) is due to ventricular tachycardia/fibrillation (VT/VF) and may occur with or without any structural or functional heart disease. The presence of myocardial edema, ischemia and/or fibrosis plays a crucial role in the pathogenesis of VT/VF, irrespective of the pathophysiologic background of the disease. Specifically, in autoimmune rheumatic diseases (ARDs), various entities such as myocardial/vascular inflammation, ischemia and fibrosis may lead to VT/VF. Furthermore, autonomic dysfunction, commonly found in ARDs, may also contribute to SCD in these patients. The only non-invasive, radiation-free imaging modality that can perform functional assessment and tissue characterization is cardiovascular magnetic resonance (CMR). Due to its capability to detect and quantify edema, ischemia and fibrosis in parallel with ventricular function assessment, CMR has the great potential to identify ARD patients at high risk for VT/VF, thus influencing both cardiac and anti-rheumatic treatment and modifying perhaps the criteria for implantation of cardioverter defibrillators.

Magnetic resonance imaging-conditional devices: Luxury or real clinical need?

Although the risk of MRI scanning on patients with conventional devices is lower than initially thought, the patient's safety can only be guaranteed when using MRI-conditional devices. The most important modifications in MRI-conditional devices include a) Reduction in ferromagnetic components to reduce magnetic attraction and susceptibility artifacts; b) Replacement of the reed switch by a Hall sensor in order to avoid unpredictable reed switch behavior; c) Lead coil design to minimize lead heating and electrical current induction; d) Filter circuitry to prevent damage to the internal power supply; and e) Dedicated pacemaker programming to prevent inappropriate pacemaker inhibition and competing rhythms. Although many companies claim to have MRI-conditional devices, adoption in clinical practice is limited because a) Not all companies have MRI-conditional devices approved for both 1.5 and 3T; b) Not all companies offer the option of unlimited MRI scanning (without an exclusion zone in the thorax); c) Certain companies allow only a 30-min MRI scanning and only in afebrile patients; and d) Despite having MRI-conditional pacemakers, certain companies do not have MRI-conditional defibrillators and CRT systems. It is clear that this new technology opens the door for MRI to a growing number of patients; however, the widespread adoption of MRI-conditional devices will depend on real-life issues, such as cost, clinical indications for such a device and the permanent education of health care professionals.

Is there a place for cardiovascular magnetic resonance conditional devices in systemic inflammatory diseases?

Rhythm disturbances and sudden cardiac death (SCD) are important manifestations of cardiac involvement in systemic inflammatory diseases (SID). The commonest events demanding the implantation of a device include ventricular tachycardia and atrioventricular block, mainly diagnosed in sarcoidosis, systemic lupus erythematosus and scleroderma. In SCD, cardiac magnetic resonance (CMR) identified areas of late gadolinium enhancement (LGE) in 71% and provided an arrhythmic substrate in 76%, while during the follow-up, the extent of LGE identified a subgroup at increased risk for future adverse events. CMR has been successfully used for detection of cardiac disease in SID, including myocarditis, coronary, microvascular and valvular disease. Additionally, SIDs have a higher probability to need MRI scanning of other organs, due to their systemic disease. These reasons support the necessity of an MRI conditional device in SIDs. A broad selection of devices, approved for the MRI environment under defined conditions allows the safe and accurate scanning of SID patients.

Incidence and risk factors of coronary heart disease in elderly patients on chronic hemodialysis.

AIM: To determine the incidence of coronary heart disease (CHD) in patients (pts) over 65 years (y) and its relation to common risk factors. METHODS: We retrospectively studied 128 hemodialysis (HD) pts (80 M and 48 F), mean age 73+/-6.5 years, mean time on HD 44.4+/-26.4 months and BMI 25.4+/-3 kg/m2. They were evaluated for: age, sex, smoking, diabetes, hypertension, left ventricular hypertrophy, secondary hyperparathyroidism (SHP), inflammation, as evidence by elevated level of hsCRP, hyperhomocysteinemia (HOC), time on HD, fluid overload and adequacy of HD. Forty-eight pts (37%) had CAD diagnosed by coronary angiography in 22 (46%) and (201)TL-chloride dipyridamole stress test in 26 (54%). RESULTS: There was a statistically significant correlation between CAD and increasing age (p<0.0001). The relative risk was significantly increased concerning: (1) male over female pts (RR: 1.95, p<0.01), (2) diabetic vs. non diabetic pts (RR: 2.09, p<0.001), (3) patients with SHP over pts with iPTH values<250 pg/ml (RR: 2.16, p<0.001), (4) hypertensive vs. non hypertensive pts (RR: 2.26, p=0.002), (5) smokers vs. non smokers (RR: 1.69, p<0.05), (6) pts with HOC over pts with normal homocysteine values (RR: 2.09, p<0.05), (7) pts with increased CRP levels over pts with normal CRP levels (RR: 1.8, p<0.01), (8) pts undergoing HD for 36 vs. 12 months (RR: 1.71, p=0.03), (9) between pts with inadequate or adequate HD (RR: 1.73, p=0.02). No significant correlation existed between CAD incidence and the other risk factors. CONCLUSIONS: Coronary heart disease incidence in elderly HD patients increases with age, male sex, diabetes, SHP, hypertension, increased CRP levels, HOC, smoking, time on HD and inadequacy of HD.