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The present study demonstrates that TVI data processing based on the inverse relationship with right ventricular volume provides an index of cardiac contractility that correlates closely with the simultaneous sinus rate modifications induced by adrenergic challenge. Similar progressive changes in the inotropic index are noticed even when the chronotropic adaptation is prevented. In contrast, a rate increase produced by overdrive pacing in the absence of contractility modifications does not affect the inotropic index [18].

TVI is sensitive to myocardial properties controlled by the sympathetic nervous system, is capable of discriminating the haemodynamic effects of intrinsic and extrinsic heart regulation, and is totally free of positive feedbacks from the cardiac rate. Therefore, this new sensor can be proposed as an advanced tool in the physiological regulation of rate-responsive pacing.

In the present animal model study, TVI sensor operation did not interfere with conventional pacemaker functions of implanted Sophós pacemakers. These results look promising since this sensor could play an important part in haemodynamic monitoring: for physiological rate adaptation, for beat-tobeat capture confirmation, in patients with neurocardiogenic syncope, for the follow-up of patients with heart failure, to indicate the best interventricular delay in CRT, and to identify arrhythmias and their haemodynamic impact in implantable cardioverter-defibrillators [10-12].

Patients with SSS should be implanted with a dual-chamber pacemaker. Alternative sites appear superior to the traditional right appendage site since they improve atrial synchrony and may reduce AF recurrences. The hig percentage of ventricular pacing in DDD mode in all studies is a common pitfall comparing physiological pacing and VVI mode is characteristic of a common pitfall: ventricular pacing has a deleterious effect on both atrial and ventricular function that may mask the real beneficial entity of atrial pacing. New pacing site in the right ventricle and use of algorithms to minimise ventricular pacing is likely to lead to more consistent positive results. In conclusion, data from the literature suggest that in patients with SSS atrial pacing from an alternative site should be used, employing algorithms to attain the highest possible percentage of atrial pacing and to reduce ventricular pacing as much as possible.

L’angiografia coronarica costituisce ancora oggi la metodica diagnostica di riferimento nello studio del circolo coronarico nativo e dei controlli degli interventi di rivascolarizzazione coronarica, sia chirurgica (confezionamento di bypass) che tramite procedure interventistiche (angioplastica percutanea-PTCA e ).

L’angiografia coronarica costituisce ancora oggi la metodica diagnostica di riferimento nello studio del circolo coronarico nativo e dei controlli degli interventi di rivascolarizzazione coronarica, sia chirurgica (confezionamento di bypass) che tramite procedure interventistiche (angioplastica percutanea-PTCA e ).

Effective haemodynamic sensing would open the way to the autoregulation of a number of pacemaker functions, which could thus be integrated into a single control system. The TVI sensor can be proposed to play this crucial role, allowing the assessment of systolic and diastolic modifications in ventricular volume by means of conventional pacing leads.

The present study demonstrates that TVI data processing based on the inverse relationship with right ventricular volume provides an index of cardiac contractility that correlates closely with the simultaneous sinus rate modifications induced by adrenergic challenge. Similar progressive changes in the inotropic index are noticed even when the chronotropic adaptation is prevented. In contrast, a rate increase produced by overdrive pacing in the absence of contractility modifications does not affect the inotropic index [18].

TVI is sensitive to myocardial properties controlled by the sympathetic nervous system, is capable of discriminating the haemodynamic effects of intrinsic and extrinsic heart regulation, and is totally free of positive feedbacks from the cardiac rate. Therefore, this new sensor can be proposed as an advanced tool in the physiological regulation of rate-responsive pacing.

MSCT coronary angiography is a promising technique for the non-invasive visualisation of coronary arteries. Based on the current literature, it is expected to have a role in the diagnosis of acute coronary syndrome. Its capability to visualise coronary artery plaques will play a role in the targeting of culprit/vulnerable plaques.

It may be said that CRT has a role in improving functional capacity over conventional right ventricular pacing in patients with left ventricular failure who require permanent ventricular stimulation and/or in those with an indication for AV nodal ablation. As for the great majority of patients with advanced heart failure and AF without conventional indications for permanent cardiac pacing — a wide and progressively expanding population in the “border zone” of current indications for CRT — no definite data are available. Some promising results from ablated patients show a favourable trend in major cardiac event reduction after CRT. More controlled clinical data are required to achieve definite conclusions about the indications for CRT in heart failure patients with AF.

ARVD is part of the group of cardiomyopathies characterised pathologically by fibrofatty replacement of the right ventricular myocardium and clinically by right ventricular arrhythmias of the LBBB pattern. Pathogenesis, prevalence, and aetiology are yet not fully known. The diagnosis of ARVD is based on the presence of structural, histological, electrocardiographic, and genetic factors. Therapeutic options include antiarrhythmic medication, catheter ablation, implantable cardioverter defibrillation, and surgery. Angiography and echocardiography lack sensitivity and specificity in the diagnosis of ARVD. MR imaging allows a three-dimensional evaluation of especially the right ventricle, and provides the most important anatomical, functional, and morphological criteria for diagnosis of ARVD within one single study. Although demonstration of morphological/functional abnormalities of the right ventricle, especially fat in the right ventricular myocardium, shows high specificity but low sensitivity, MR imaging appears to be the optimal imaging technique for detection and follow-up of clinically suspected ARVD. Positive MR imaging findings, based on the criteria of McKenna et al. [16], should be used as important additional criteria in the clinical diagnosis of ARVD, although negative MR imaging findings do not rule out ARVD.