ECG evaluation in 11 949 Italian teenagers: results of screening in secondary school

AIM

There is lack of evidence regarding the screening role of ECG for sudden cardiac death (SCD) prevention. Our aim was to evaluate the prevalence of ECG abnormalities among teenagers according to sport participation and competitive status.

METHODS

Eleven thousand nine hundred and forty-nine Italian pupils from 179 secondary schools (13-19 years) were consecutively enrolled. ECG abnormalities were divided into minor and major. Medical history, clinical examination and sport activity information were acquired. Further evaluations were suggested in case of major ECG abnormalities. Follow-up was performed at 2 years.

RESULTS

N = 1945 (16%) pupils had ECG abnormalities. Major ECG abnormalities were detected in 13% of the cohort, minor in 34%. ECG abnormalities were more common in nonathletes compared with athletes. A diagnosis of cardiac disease was reached in 25 (1.6%) of the pupils with major ECG abnormalities.

CONCLUSION

ECG abnormalities are common among young populations and more prevalent in nonathletes. Among pupils with major ECG abnormalities 1.6% had a cardiac disease diagnosis. Our results are in line with the data supporting ECG screening in the general young population.

Lung assist devices influence cardio-energetic parameters: Numerical simulation study

We aim at an analysis of the effects mechanical ventilators (MVs) and thoracic artificial lungs (TALs) will have on the cardiovascular system, especially on important quantities, such as left and right ventricular external work (EW), pressure-volume area (PVA) and cardiac mechanical efficiency (CME). Our analyses are based on simulation studies which were carried out by using our CARDIOSIM(©) software simulator. At first, we carried out simulation studies of patients undergoing mechanical ventilation (MV) without a thoracic artificial lung (TAL). Subsequently, we conducted simulation studies of patients who had been provided with a TAL, but did not undergo MV. We aimed at describing the patient's physiological characteristics and their variations with time, such as EW, PVA, CME, cardiac output (CO) and mean pulmonary arterial/venous pressure (PAP/PVP). We were starting with a simulation run under well-defined initial conditions which was followed by simulation runs for a wide range of mean intrathoracic pressure settings. Our simulations of MV without TAL showed that for mean intrathoracic pressure settings from negative (-4 mmHg) to positive (+5 mmHg) values, the left and right ventricular EW and PVA, right ventricular CME and CO decreased, whereas left ventricular CME and the PAP increased. The simulation studies of patients with a TAL, comprised all the usual TAL arrangements, viz. configurations "in series" and in parallel with the natural lung and, moreover, hybrid configurations. The main objective of the simulation studies was, as before, the assessment of the hemodynamic response to the application of a TAL. We could for instance show that, in case of an "in series" configuration, a reduction (an increase) in left (right) ventricular EW and PVA values occurred, whereas the best performance in terms of CO can be achieved in the case of an in parallel configuration.

Interactive simulator for e-Learning environments: a teaching software for health care professionals

There is an established tradition of cardiovascular simulation tools, but the application of this kind of technology in the e-Learning arena is a novel approach. This paper presents an e-Learning environment aimed at teaching the interaction of cardiovascular and lung systems to health-care professionals. Heart-lung interaction must be analyzed while assisting patients with severe respiratory problems or with heart failure in intensive care unit. Such patients can be assisted by mechanical ventilatory assistance or by thoracic artificial lung.

“In silico” cardiovascular simulator was experimented during a training course given to graduate students of the School of Specialization in Cardiology at ‘Sapienza’ University in Rome.

The training course employed CARDIOSIM^©: a numerical simulator of the cardiovascular system. Such simulator is able to reproduce pathophysiological conditions of patients affected by cardiovascular and/or lung disease. In order to study the interactions among the cardiovascular system, the natural lung and the thoracic artificial lung (TAL), the numerical model of this device has been implemented. After having reproduced a patient’s pathological condition, TAL model was applied in parallel and hybrid model during the training course.

Results obtained during the training course show that TAL parallel assistance reduces right ventricular end systolic (diastolic) volume, but increases left ventricular end systolic (diastolic) volume. The percentage changes induced by hybrid TAL assistance on haemodynamic variables are lower than those produced by parallel assistance. Only in the case of the mean pulmonary arterial pressure, there is a percentage reduction which, in case of hybrid assistance, is greater (about 40%) than in case of parallel assistance (20-30%).

At the end of the course, a short questionnaire was submitted to students in order to assess the quality of the course. The feedback obtained was positive, showing good results with respect to the degree of students’ learning and the ease of use of the software simulator.

Mechanical ventilation and thoracic artificial lung assistance during mechanical circulatory support with PUCA pump: in silico study

Patients assisted with left ventricular assist device (LVAD) may require prolonged mechanical ventilatory assistance secondary to postoperative respiratory failure. The goal of this work is the study of the interdependent effects LVAD like pulsatile catheter (PUCA) pump and mechanical ventilatory support or thoracic artificial lung (TAL), by the hemodynamic point of view, using a numerical simulator of the human cardiovascular system. In the simulator, different circulatory sections are described using lumped parameter models. Lumped parameter models have been designed to describe the hydrodynamic behavior of both PUCA pump and thoracic artificial lung. Ventricular behavior atrial and septum functions were reproduced using variable elastance model. Starting from simulated pathological conditions we studied the effects produced on some hemodynamic variables by simultaneous PUCA pump, thoracic artificial lung or mechanical ventilation assistance. Thoracic artificial lung was applied in parallel or in hybrid mode. The effects of mechanical ventilation have been simulated by changing mean intrathoracic pressure value from -4 mmHg to +5 mmHg. The hemodynamic variables observed during the simulations, in different assisted conditions, were: left and right ventricular end systolic (diastolic) volume, systolic/diastolic aortic pressure, mean pulmonary arterial pressure, left and right mean atrial pressure, mean systemic venous pressure and the total blood flow. Results show that the application of PUCA (without mechanical ventilatory assistance) increases the total blood flow, reduces the left ventricular end systolic volume and increases the diastolic aortic pressure. Parallel TAL assistance increases the right ventricular end diastolic (systolic) volume reduction both when PUCA is switched "ON" and both when PUCA is switched "OFF". By switching "OFF" the PUCA pump, it seems that parallel thoracic artificial lung assistance produces a greater cardiac output (respect to hybrid TAL assistance). Results concerning PUCA and TAL interaction produced by simulations cannot be compared with "in vivo" results since they are not presented in literature. But results concerning the effects produced by LVAD and mechanical ventilation have a trend consistent with those presented in literature.

In silico study of the haemodynamic effects induced by mechanical ventilation and biventricular pacemaker

In silico modeling of the cardiovascular system (CVS) can help both in understanding pharmacological or pathophysiological process and in providing information which could not be obtained by means of traditional clinical research methods due to practical or ethical reasons. In this work the numerical CVS was used to study the effect of interaction between mechanical ventilation and biventricular pacemaker by haemodynamic and energetic point of view. Starting from literature data on patients with intra and/or inter-ventricular activation time delay and treated using biventricular pacemaker, we used in silico simulator to analyse the effects induced by mechanical ventilatory assistance (MVA). After reproducing baseline and CRT conditions, the MVA was simulated changing the mean intrathoracic pressure value. Results show that simultaneous application of CRT and MVA yields a reduction of cardiac output, left ventricular end-diastolic and end-systolic volume when positive mean intrathoracic pressure is applied. In the same conditions, when MVA is applied, left ventricular ejection fraction, mean left (right) atrial and pulmonary arterial pressure increase.

Redox imbalance of red blood cells impacts T lymphocyte homeostasis: implication in carotid atherosclerosis

Oxidative stress and immune/inflammatory responses are key pathogenetic factors of atherosclerotic disease. In this contest, mechanisms that regulate survival and death of immune cells may be relevant. Previous studies have demonstrated that red blood cells (RBCs) are physiologically able to inhibit apoptosis and to promote proliferation of activated T lymphocytes from healthy subjects. The aim of the present study was to evaluate whether RBCs from patients with carotid atherosclerosis maintain their property to modulate T cell homeostasis. Peripheral blood lymphocytes (PBLs) obtained from healthy subjects were activated in vitro by phytohemagglutinin in the presence/absence of RBCs from patients with carotid atherosclerosis or of in vitro oxidised RBCs from healthy subjects. Levels of reactive oxygen species (ROS) and aging markers of RBCs as well as susceptibility to apoptosis of PBLs were evaluated by flow cytometry. PBL proliferation was evaluated by 3H-methyl-thymidine incorporation assay whereas secretion of cytokines, analysed in view of their key role in T cell function, was assessed by ELISA. Levels of ROS and phosphatidyl-serine externalisation, a sign of RBC aging, resulted significantly higher in RBCs from patients than in those from healthy subjects, whereas surface glycophorin A expression and reduced glutathione content did the opposite. Unlike RBCs obtained from healthy subjects, RBCs from patients and in vitro oxidised RBCs did not protect activated T lymphocytes from apoptosis. Hence, RBCs from patients with carotid atherosclerosis, probably due to their oxidative imbalance, impact T cell integrity and function. Our results suggest a new regulatory role for RBCs in atherosclerosis.

Pathophysiology of dynamic left ventricular outflow tract obstruction in a critically ill patient

Left ventricular outflow tract obstruction is not a rare problem in the intensive care units and can precipitate hemodynamic shock unresponsive to catecholamine therapy. The use of echocardiographic examination is extremely important in recognizing this phenomenon and its underlying conditions, finally identifying the most appropriate therapeutic strategy. The simple correction of one or more of these factors can dramatically change patients clinical outcome. We report the clinical case of a 72-year-old man who developed hemodynamic shock in the intensive care unit. Hypovolemia, catecholamine infusion, and mechanical ventilation induced geometric modification of the left ventricle causing a systolic anterior motion of the mitral anterior leaflet and a severe subaortic gradient. Simple restoration of fluids and discontinuation of medical therapy dramatically changed the outcome of the patient. A review of the medical literature has been carried out to deeply investigate pathophysiology of left ventricular outflow tract obstruction in critically ill patients.

Syncope caused by iatrogenic hyperkalemia

Symptomatic bradycardia in the emergency department may have several causes (excessive vagal tone, drug toxicity, acute myocardial ischemia, sick sinus syndrome, heart block, and electrolyte imbalance); among these, hyperkalemia may develop as a complication of chronic medical treatment with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and must be considered in the early approach to the bradyarrhythmic patient with possible electrocardiographic signs of hyperkalemia. We report a case of an 87-year-old woman with a clinical history of chronic angiotensin-receptor blocker consumption that led her to dangerous bradyarrhythmia, cardiogenic syncope, and risk of sudden cardiac death.

Home defibrillation: a feasibility study in myocardial infarction survivors at intermediate risk of sudden death

BACKGROUND

Out-of-hospital cardiac arrest occurs at home in 65-80% of cases and is often witnessed. We designed a study to explore the feasibility of a home defibrillation program (a) evaluating the retention of cardiopulmonary resuscitation and automated external defibrillators (AED) use skills (BLSD) (b) assessing the impact on anxiety, depression, and quality of life and (c) recording the critical issues emerging from program implementation.

METHODS

Thirty-three post-myocardial infarction patients and their 56 relatives received BLSD training and an AED. Assessment of BLSD skills, levels of anxiety, and depression and quality of life were scheduled every 3 months for 1 year or until a common stopping date.

RESULTS

Overall BLSD score was 26 +/- 3 at baseline vs. 22 +/- 5 at 3 months (P < .0001), 21 +/- 6 at 6 months (P < .0001), 22 +/- 4 at 9 months (P < .0001) and 23 +/- 5 at 12 months (P = .001). Conversely, the BLSD component AED use" remained stable throughout the study. Quality of life, anxiety, and depression scores remained constant. Compliance to BLSD retraining sessions and AEDs checks decreased over time and was influenced by a concomitant clinical appointment.

CONCLUSIONS

BLSD performance of families of post-myocardial infarction patients decreases over time, even though the ability to operate AEDs appears to be the least affected component. Compliance with retraining sessions and AED checks declines over time and is improved if they are combined with clinical appointments. The implementation of a home defibrillation program does not affect anxiety, depression, or the quality of life.

Levosimendan improves hemodynamics and coronary flow reserve after percutaneous coronary intervention in patients with acute myocardial infarction and left ventricular dysfunction

BACKGROUND

Positive inotropic agents may be associated with increasing myocardial ischemia or malignant arrhythmias. Levosimendan, a new calcium sensitizer, with its little effect on myocardial oxygen demand is better tolerated by patients with acute coronary syndromes. We evaluated the acute effects of levosimendan on hemodynamics and coronary flow velocities in patients with left ventricular (LV) dysfunction undergoing percutaneous coronary interventions (PCIs) for an acute myocardial infarction (AMI).

METHODS

Patients with AMI and LV dysfunction undergoing primary PCI were randomized to intravenous infusion of levosimendan (10 minutes bolus with 12 microg/kg followed by 0.1 microg/kg per minute for 24 hours) or placebo, 10 minutes after a primary PCI. Evaluation of hemodynamics and of coronary flow reserve (CFR) were performed at baseline and after bolus.

RESULTS

Twenty-six consecutive patients (mean age 57 +/- 5.4 years, 18 males) were included into the study. At baseline, mean values of hemodynamics and coronary flow velocities were comparable between groups. After bolus, patients with levosimendan (n = 12) showed a significant decrease of pulmonary capillary wedge pressure (from 24 to 19 mm Hg) and a significant increase of cardiac index (from 1.8 to 2.4 L/m2 per minute) resulting in a significant decrease of systemic vascular resistance (from 1366 to 1075 [dyne . s]/cm2). Moreover, CFR on infarct-related artery and on reference vessel significantly improved in patients treated with levosimendan (from 1.6 to 2.0 and from 2.1 to 2.4, respectively). On the other hand, no statistically significant changes have been observed in the placebo group (n = 14).

CONCLUSIONS

Levosimendan, given intravenously after a PCI procedure in patients with AMI and LV dysfunction, significantly improves hemodynamics and CFR, compared with placebo.

Telecar: an Italian telecardiology project

The Telecar (tele-assistance cardiology) project was an example of tele-assistance between health centres of the Regione Lazio in Italy. The project was approved by the Ministry of Health, financed with 500,000,000 lire and carried out by an operative station within 'La Sapienza' University (Rome). About 40 of the health centres in Lazio that did not have cardiologists or electrocardiography (ECG) equipment were provided with telematic instruments (Cardiophone and fax). With this equipment, they were able to transmit ECG signals and receive copies of ECG reports. The 40 health centres included first-aid clinics, 'guardia medica' surgeries and community centres. The project was carried out between 1989 and 1992. During these three years the health centres transmitted a total of 4807 ECGs, 2057 (43%) of which were routine, the remaining 2750 (57%) being suspected emergencies. Of the suspected emergencies, 681 cases (25%) had a confirmed abnormality. We can confirm that telematic aids are very important for an operative station, where all kinds of emergencies must be dealt with.

Equilibrium radionuclide ventriculography in Duchenne's cardiomyopathy

Rest and stress (handgrip) equilibrium radionuclide ventriculography was performed in 20 patients with Duchenne muscular dystrophy. The mean value of LVEF was normal, but two patients showed values below 35% and another two patients values over 70%. Mean regional wall motion values were less than 2 in lateral (posterior and inferior) and septal walls. Handgrip usually produced a reduction of LVEF and regional wall motion: in three cases severe decrease of motility was observed. Equilibrium ventriculography appears to be useful in the selection of patients with high functional cardiac involvement, integrating the characteristic ECG and echography, and, perhaps, in the assessment of myocardial tolerance to physical therapy.