Biomedical subjects

Paolo Diotallevi

Publications and source records attributed to Paolo Diotallevi.

5 recordsLinked to original sources

PubMed2006

The risk profile for obstructive sleep apnea does not affect the recurrence of atrial fibrillation.

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to increased prevalence and recurrence of atrial fibrillation (AF). We hypothesized that OSA may aggravate AF in patients with pacemakers implanted for sinus bradycardia who had documented paroxysmal AF. METHODS: Seventy-two patients (36 M, aged 77 +/- 6 years) completed the study. All patients received a dual-chamber pacemaker equipped with diagnostic and preventive functions for AF. OSA was diagnosed with the Berlin Questionnaire, which is validated to identify patients with OSA. Four-month continuous pacemaker recordings were collected for all patients. RESULTS: OSA was diagnosed in 28% of patients. Patients at high risk for OSA (HR group) and patients at low risk for OSA (LR group) were equivalent for gender, age, and body mass index. The rate of hypertension was higher in HR than in LR group (90% vs 44%, P < 0.01). The prevalence of paroxysmal AF during the study period was similar in HR and LR group (53% vs 44%, P = NS). Overall number of AF episodes per month was not significantly different between HR and LR group (7 +/- 13 vs 36 +/- 122, P = NS). Similarly, AF burden (AF%) was not significantly different between HR and LR group (0.3 +/- 0.6 vs 2.0 +/- 4.8, P = NS). Circadian distribution of AF episodes was similar in both groups. CONCLUSION: Long-term pacemaker recording of AF recurrence, AF burden, and its circadian distribution is similar in patients with paroxysmal AF at high risk for OSA and those at low risk for OSA.

Aged↗

PubMed2005

A new endocardial "over-the-wire" or stylet-driven left ventricular lead: first clinical experience.

Transvenous left ventricular (LV) leads are primarily inserted "over-the-wire" (OTW). However, a stylet-driven (SD) approach may be a helpful alternative. A new polyurethane-coated, unipolar LV lead can be placed either by a stylet or a guide wire, which can be inserted into the lead body from both ends. The multicenter OVID study evaluates the clinical performance of this new steroid- and nonsteroid eluting lead. The primary endpoint is the LV lead implant success rate after identification of the coronary sinus (CS). Secondary endpoints include complication rate, short- and long-term lead characteristics, overall procedure and LV lead placement duration, total fluoroscopy time, and lead handling characteristics ratings. To date, 96 patients with heart failure (68 +/- 9 years old, 76% men) are enrolled. The CS was identified in 95 patients and, in 85 (88.5%), the LV lead was successfully implanted. The final lead positioning was lateral in 41%, posterolateral in 35%, anterolateral in 18%, and great cardiac vein in 6% of patients. In 70%, the 85 successful implantations, both stylet-driven and guide-wire techniques were used, a stylet only was used in 22%, and a guide wire only in 8%. Mean overall duration of 85 successful procedures was 112 +/- 40 minutes, total fluoroscopy time 28 +/- 15 minutes, and the duration of LV lead placement was 35 +/- 29 minutes. During a 3-month follow-up, the loss of LV capture occurred in three and phrenic nerve stimulation in six patients. The mean long-term pacing threshold is 0.8 V/0.5 ms and pacing impedance is 550 Omega. The OVID data suggest that these new leads are safe and effective. The choice of both OTW and SD techniques during lead implantation offers greater procedural flexibility.

Adult↗

PubMed2005

An algorithm for verifying biventricular capture based on evoked-response morphology.

Cardiac resynchronization therapy relies on consistent beat-by-beat myocardial capture in both ventricles. A pacemaker ensuring right (RV) and left ventricular (LV) capture through reliable capture verification and automatic output adjustment would contribute to patients' safety and quality of life. We studied the feasibility of an algorithm based on evoked-response (ER) morphology for capture verification in both the ventricles. RV and LV ER signals were recorded in 20 patients (mean age 72.5 years, range 64.3-80.4 years, 4 females and 16 males) during implantation of biventricular (BiV) pacing systems. Leads of several manufacturers were tested. Pacing and intracardiac electrogram (IEGM) recording were performed using an external pulse generator. IEGM and surface-lead electrocardiogram (ECG) signals were recorded under different pacing conditions for 10 seconds each: RV pacing only, LV pacing only, and BiV pacing with several interventricular delays. Based on morphology characteristics, ERs were classified manually for capture and failure to capture, and the validity of the classification was assessed by reference to the ECG. A total of 3,401 LV- and 3,345 RV-paced events were examined. In the RV and LV, the sensitivities of the algorithm were 95.6% and 96.1% in the RV and LV, respectively, and the corresponding specificities were 91.4% and 95.2%, respectively. The lower sensitivity in the RV was attributed to signal blanking in both channels during BiV pacing with a nonzero interventricular delay. The analysis revealed that the algorithm for identifying capture and failure to capture based on the ER-signal morphology was safe and effective in each ventricle with all leads tested in the study.

Aged↗

PubMed2004

Activation of the contact system and inflammation after thrombolytic therapy in patients with acute myocardial infarction.

Thrombolytic therapy activates the contact system, and factor XII activation may activate the coagulation cascade and inflammation. It is not known whether an early inflammatory response is induced by thrombolytic therapy in patients with acute myocardial infarction (AMI). We prospectively measured the plasma levels of activated factor XII, cleaved kininogen, prothrombin fragment 1 + 2 (as indexes of the contact phase and coagulation activation), and interleukin-6 and C-reactive protein (CRP) (as indexes of inflammation) in 39 patients hospitalized for AMI within 12 hours of symptom onset: 26 receiving thrombolytic therapy and 13 heparin alone. Blood samples were collected at baseline and after 90 minutes and 24 hours. Patients undergoing thrombolysis had a significant early increase in activated factor XII (from 2.2 ng/ml at baseline to 4.7 ng/ml after 90 minutes; p = 0.0001), cleaved kininogen (from 26% to 37%; p = 0.001), and fragment 1 + 2 (from 1.4 to 2.1 nmol/L; p = 0.0001), whereas the 24-hour levels were similar to baseline levels. The levels of interleukin-6 significantly increased during the first 90 minutes (from 3.9 to 6.3 microg/ml; p = 0.001), and were even higher after 24 hours (11.9 ng/ml, p = 0.0001). CRP levels increased only after 24 hours (p = 0.0001). There were no changes in these parameters in patients receiving heparin alone, except for a 24-hour increase in interleukin-6 and CRP levels. Thus, in patients with AMI receiving thrombolytic therapy, early activation of inflammation parallels the activation of the contact system and the coagulation cascade, which might contribute to microvascular obstruction and reperfusion injury.

C-Reactive Protein↗

PubMedDate not supplied

Noncontrast CT assessment of early cerebral ischaemia.

PURPOSE: To assess the diagnostic value of early signs of ischaemic cerebral infarction detected by unenhanced CT in the first 6-10 hours. MATERIAL AND METHODS: We reviewed the CT examinations of 42 patients (mean age: 61 years, range: 35-79) with suspected ischaemic stroke. We assessed CT findings at 6-10 hours of the onset of stroke for hemilateral evidence of main cerebral artery hyperdensity, sulcal effacement, liquoral space asymmetry, hypodensity of grey matter. The CT scans were performed without contrast medium. RESULTS: The topographic pattern of cerebral infarctions was: middle cerebral artery territory in 25 patients, anterior cerebral in 9, striatal lacunar infarction in 2, posterior junctional infarction in 5, anterior junctional infarction in 1. Early signs of infarction were present in 24 patients (57%). CT scans showed early signs in 20 cases (80%) of middle cerebral infarctions; 8 (32%) had middle cerebral artery hyperdensity; 3 (12%) had middle cerebral artery hyperdensity and sulcal effacement; 4 (16%) had sulcal effacement; 2 (8%) had liquoral space asymmetry; 3 (12%) had hypodensity of grey matter and liquoral space asymmetry. CT scans showed early signs in 4/9 (44%) of anterior cerebral infarctions. Sensitivity and specificity of early CT to cerebral infarction was 57% and 100%. The three cases with both hyperdense middle cerebral artery and sulcal effacement died of transtentorial herniation within the 10th day. The seven other deaths occurred in patients without early signs or particular patterns appearing in subsequent CT. DISCUSSION: In the management of ischaemic stroke the aim of neuroradiologic methods is to provide exact direction to immediate therapy by early diagnosis. In such cases the use of CT scanning aims at detecting signs of two main alterations of infarction: vascular occlusion and brain oedema. Middle cerebral artery hyperdensity, showing steady correspondence to infarction site and frequent disappearance on the follow-up CT, is indicative of embolic occlusion. Signs of "mass effect" are evident from the early stages in relation to the substantial concomitance of various types of brain oedema. The semeiology discussed in this study is more clearly detectable in middle cerebral artery infarction because this territory is the main site of embolic occlusion, and its larger size increases the "mass effect" due to oedema. The sensitivity obtained in this study is among the lowest values reported, which likely relates to our choice to use short scan times.

Adult↗