The in-ear region as a novel anatomical site for ECG signal detection: validation study on healthy volunteers.

PURPOSE: Early detection of cardiac arrhythmias is a major opportunity for mobile health, as wearable devices nowadays available can detect single-lead electrocardiogram (ECG). The study aims to validate the in-ear region as a new anatomical site for ECG signal detection and looks towards designing innovative ECG wearable devices. METHODS: We performed ECG using KardiaMobile device (AliveCor®) on 35 healthy volunteers. First, ECG was detected by standard modality using both hands. Then, ECG was detected using the left in-ear region instead of the right hand. All the recorded ECGs were analyzed by the device and by two cardiologists in blind testing. RESULTS: We successfully collected 70 ECGs performed on 35 volunteers (male 54%, age 39.1 ± 10.7 years; BMI 22.9 ± 2.89 kg/m2) with no differences observed by KardiaMobile in ECG reports detected in the two different modalities. All the ECGs were reported as normal by the device and the two cardiologists. Moreover, linear regression analysis showed good correlation between the amplitude (mV) of P (r = 0.76; r2 = 0.57; p < 0.0001) and QRS waves (r = 0.81; r2 = 0.65; p < 0.0001), the intervals (ms) of PR (r = 0.91; r2 = 0.83; p < 0.0001; LOA - 0.60-0.41; CC = 0.91), QRS (r = 0.78; r2 = 0.61; p < 0.0001; LOA - 0.49-0.43; CC = 0.78), QT (r = 0.85; r2 = 0.71; p < 0.0001; LOA - 1.31-1.20; CC = 0.85), and heart rate (r = 0.94; r2 = 0.89; p < 0.0001; LOA - 7.82-7.76; CC = 0.94) detected in two different modalities. CONCLUSION: The in-ear region is a reliable novel anatomical site for ECG signal detection in normal healthy subjects. Further studies are needed to validate this new ECG detection modality also in case of cardiac arrhythmias and to support the development of new wearable devices.

Performance and clinical comparison between left ventricular quadripolar and bipolar leads in cardiac resynchronization therapy: Observational research.

AIM: To evaluate Attain Performa (Medtronic, Dublin, Ireland) quadripolar lead performance in clinical practice and, secondarily, to compare its long term clinical outcomes vs bipolar leads for left ventricular (LV) pacing. METHODS AND RESULTS: We retrospectively analyzed clinical, procedural and follow-up data of 215 patients implanted with a quadripolar lead. One hundred and twenty one patients implanted with bipolar lead were selected to compare long-term clinical outcomes. The quadripolar lead was implanted in the target vein in 196 patients (91%) without acute dislodgements. In 50% of patients the chosen final pacing configuration at implant would not have been available with bipolar leads. A dedicated quadripolar pacing vector was chosen more frequently when the LV tip location was apical than otherwise (65.6% vs 42.7%, p=0.003). After a median follow-up of 14 months, the LV pacing threshold was less than 2.5V at 0.4ms in 98 patients (90%) with a safety margin between phrenic nerve and LV pacing threshold >3V in 97 patients (89%). We observed a slight trend toward a lower risk of heart failure worsening and a lower incidence of ventricular arrhythmias and pulmonary congestion in patients implanted with quadripolar leads compared with the control group. CONCLUSION: Quadripolar leads improve the management of phrenic nerve stimulation at no trade-off with pacing threshold and lead stability. Quadripolar leads seems to be associated with a lower incidence of VT/VF and pulmonary congestion, when compared with bipolar leads, but further investigations are necessary to confirm that this positive effect is associated with better LV reverse remodeling.

Noninvasive prediction of sudden death and sustained ventricular tachycardia after acute myocardial infarction using a neural network algorithm.

BACKGROUND: The early and accurate noninvasive identification of postinfarction patients at risk of sudden death and sustained ventricular tachycardia (arrhythmic events) still remains an unsolved problem. The aim of the present study was to identify the combination of clinical and laboratory noninvasive variables, easy to obtain in most patients, that best predicts the occurrence of arrhythmic events after an acute myocardial infarction. METHODS: Four hundred and four consecutive patients with acute myocardial infarction were enrolled and followed for a median period of 21.4 months. In each patient, 61 clinical and laboratory noninvasive variables were collected before hospital discharge and used for the prediction of arrhythmic events using an artificial neural network. RESULTS: During follow-up, 13 (3.2%) patients died suddenly and 11(2.5%) had sustained ventricular tachycardia. The neural network showed that the combination best predicting arrhythmic events included: left ventricular failure during coronary care stay, ventricular dyskinesis, late potentials, number of ventricular premature depolarizations/hour, nonsustained ventricular tachycardia, left ventricular ejection fraction, bundle branch block and digoxin therapy at discharge. The neural network algorithm allowed identification of a small high-risk patient subgroup (12% of the study population) with an arrhythmic event rate of 46%. The sensitivity and specificity of the test were 96 and 93% respectively. CONCLUSIONS: These results suggest that, in postinfarction patients, it is possible to predict early and accurately arrhythmic events by noninvasive variables easily obtainable in most patients. Patients identified as being at risk are candidates for prophylactic antiarrhythmic therapy.

[Permanent junctional reciprocating tachycardia (Coumel type): an unusual location of a retrograde accessory pathway]. / Tachicardia reciprocante giunzionale permanente (tipo Coumel): un'inconsueta localizzazione della via accessoria retrograda.

Permanent junctional reentrant tachycardia (PJRT) is an uncommon form of tachycardia that is usually due to an atrioventricular reentry via a right posteroseptal accessory pathway with decremental properties. We describe a case of PJRT that showed evidence of two accessory pathways located both left and right. A 63-year-old woman was referred to our institution for radiofrequency (RF) ablation of a permanent form of regular narrow QRS tachycardia (T) (cycle length 520 ms) with long RP interval (380 ms); P wave was negative in inferior leads, negative in D1 and flat in aVL. During sinus rhythm, AH and HV intervals were 110 ms and 50 ms respectively. The atrioventricular anterograde conduction curve was continuous. A decremental retrograde conduction via a left posterior pathway until ventricular effective refractory period (210 ms) was evident. Tachycardia inducible with both atrial and ventricular programmed stimulation was almost incessant. During tachycardia, a premature ventricular depolarization delivered when His bundle was refractory was able to advance the next atriogram, and tachycardia could be interrupted by a ventricular depolarization without atrial capture. During right atrial mapping, an earliest atrial activation was found in the mid-septal position just above the coronary sinus ostium and RF application caused a transient interruption of T (3 minutes). Tachycardia resumed with basal characteristics, but no evidence of earlier right atrial activation was found during atrial mapping. Successful RF ablation was performed via retrograde aortic catheterization in the left posterior region. This case showed evidence of a left posterior pathway causing PJRT. However, the transient successful ablation in the right mid-septal region and the lack of evidence of right early atrial activation after RF application could account for the presence of an additional right accessory pathway or a strand of the same broad left pathway.

[AIDS-related neoplasms: a clinico-radiological study]. / Neoplasie correlate con AIDS: studio clinico-radiologico.

Although high-grade non-Hodgkin's lymphoma (NHL) and an unusually aggressive form of Kaposi's sarcoma (KS) remain the most common malignancies seen in AIDS patients, other tumors such as cervical cancer, Hodgkin's disease and others, have been increasingly observed, probably because these patients now live longer. We report the imaging findings of 80 AIDS patients with pathologically confirmed neoplasms from a series of 340 AIDS patients examined 1986-1994. Twenty-four of 80 patients had NHL, 4 Hodgkin's disease, 31 KS, 4 cervical cancer, 2 leukemia, 2 testicular, 1 larynx, 2 lung, 2 breast, 1 esophagus, 1 stomach, 1 liver, 2 kidney and 3 adrenal carcinomas. Twenty of 24 NHLs exhibited extranodal involvement--to the liver (13/24), brain (9/24), lung (7/24) and gastrointestinal tract (6/24). Visceral KS involved the gastrointestinal tract (6/32), lung (4/32) and liver (2/32). The most accredited pathogenetic theories concerning the role of HIV infection in oncogenesis advocate the effect of multiple growth factors produced by HIV-infected lymphocytes (KS) or the disregulation of B-cells caused by T-cell destruction (NHL). The atypical morphostructural features of AIDS-related tumors are discussed--e.g., atypical presentation, occurrence in younger individuals, aggressive clinical course and poor response to conventional therapy--together with the differential diagnostic problems, especially vs. opportunistic infections.