CGMP Levels Following ANF Challenge are Markers of Subsequent Successful Reversion of Lone Atrial Fibrillation to Sinus Rhythm

The aim of the present study was to assess whether cGMP release to ANP stimulation can be a biochemical marker of subsequent successful electrical cardioversion of lone atrial fibrillation to sinus rhythm. For this purpose, we studied 13 patients with chronic, lone atrial fibrillation of less than one year's duration who presented to our laboratory for electrical therapy of their arrhythmia. Prior to electrical cardioversion, peripheral venous cGMP levels were assessed at baseline and following an tntravenous challenge of 50 Ug human ANP. Venous blood samples for cGMP assessment were taken a) at baseline, b) 5 and 10 mins after the end of ANP infusion. ANOVA of repeated measures was used for statistical analysis. Eight of the study patients were successfully cardioverted to sinus rhythm, while the remaining 5 were not. Although no difference was noted between the two groups regarding the mean time of arrhythmia duration as well as left atrial and ventricular dimensions, ANP stimulation provoked significantly greater cGMP release in patients whose arrhythmia reverted to sinus rhythm, when compared with that of patients whose arrhythmia persisted (p<0.001). Therefore, cGMP levels following ANP challenge might discriminate between patients with chronic AF who are going to be successfully cardioverted and those who are not. These findings imply that the underlying atrial disease might be different in extent/nature between patients with lone AF responsive to cardioversion and those with resistant arrhythmia.     

Differential Effect of Biventricular and Right Ventricular DDD Pacing on Coronary Flow Reserve in Patients With Ischemic Cardiomyopathy

CRT and Coronary Flow Reserve. Background: Cardiac resynchronization therapy (CRT) has become a mainstay in heart failure management. There are also indications that upgrading of existing pacemakers to CRT systems may be of benefit. The aim of this study was to assess the effect of biventricular (BiV), compared with right ventricular (RV), pacing, on coronary flow reserve (CFR), in patients with ischemic cardiomyopathy. Methods and Results: From our database of heart failure patients implanted with BiV pacemakers, 20 patients (10 responders and 10 non‐responders to CRT) were randomly selected. Left anterior descending artery coronary flow reserve was measured invasively, under BiV and RV pacing, using intracoronary adenosine to induce hyperemia. In all the 20 patients, there was a significant difference in the pairwise comparison between CFR recorded during BiV and RV pacing (mean difference 0.15, 95% confidence interval 0.07–0.23, P = 0.001). When comparing responders to non‐responders, there was a significant difference as to the effect of BiV, compared with RV, pacing on CFR: mean difference (BiV minus RV CFR) was 0.26 ± 0.06 (95% confidence interval 0.13–0.39; P = 0.002), while in non‐responders the difference was 0.04 ± 0.03 (95% confidence interval ?0.02 to 0.10; P = 0.168). Conclusion: BiV pacing is overall associated to higher CFR, compared with RV DDD pacing. This difference is almost exclusively attributable to the beneficial effect of CRT on coronary flow reserve in CRT‐responders. This effect may contribute to the beneficial action of resynchronization in the failing heart and can be viewed in the context of reports of the usefulness of upgrading RV pacemakers to CRT systems. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1233‐1239, November 2010)     

Bare Stent Implantation Through a Side Slot of Another Stent in a Bifurcation Lesion

A case of a patient with significant (≈ 90%) stenosis of the circumflex at its origin from the left main artery and of the first marginal branch, 20 mm after its origin from the circumflex, is described. The case was treated with implantation of two stents, one at the marginal and another at the circumflex through a side slot of the first stent.     

Disorders of the Autonomic Nervous System in Patients With Brugada Syndrome: A Pilot Study

Autonomic Disorders in Brugada Syndrome . Introduction: The aim of this study was to examine autonomic disorders in patients with Brugada syndrome by performing a cardiac sympathetic innervation evaluation, a head‐up tilt‐test (HUT) and heart rate variability (HRV) analysis. Methods and Results: We enrolled 20 patients with Brugada syndrome (mean age 42.5 ± 8.8 years), 9 with spontaneous and 11 with an induced type 1 electrocardiogram (ECG) in the setting of symptoms and 20 age‐matched controls. All subjects underwent a HUT with parallel measurements of plasma catecholamines and cortisol, a ¹²³I‐metaiodobenzylguanidine single photon emission tomography, and HRV evaluation. Ten control subjects participated in the innervation portion of the study. The tilt‐test with clomipramine challenge was positive in 15 of 20 (75%) patients (7 spontaneous, 8 induced) and in 1 in controls (P < 0.01). A sympathoadrenal imbalance was shown in positive tests. The pattern of innervation in all groups was heterogenic and similar to controls with a trend towards lower measurements in patients with a spontaneous type 1 ECG and a positive HUT. HRV analysis did not reveal any significant differences during day and night. Four patients (20%) had sustained ventricular arrhythmias during a follow‐up of 31.1 ± 8.6 months, but no correlations with innervation or response to tilting were found. Conclusion: A high susceptibility to vasovagal syncope was observed in patients with Brugada syndrome, which could be disease‐related symptoms. Conversely, sympathetic innervation was observed to follow a physiological, heterogenic pattern; however, these factors did not have prognostic value for life‐threatening arrhythmias. (J Cardiovasc Electrophysiol, Vol. pp. 773‐780, July 2010)     

Coronary Angioplasty and Stent Placement by a Single Operator Without the Assistance of a Second Interventional Cardiologist and Nurse

Traditionally, not only the use of several devices, but plain angioplasty is performed by at least two interventional cardiologists and one specialized nurse. The aim of our study was to investigate the feasibility, effectiveness, and safety of angioplasty with stent implantation by a single operator, without the assistance of a second interventional cardiologist or a nurse. A total of 153 patients participated. Angioplasty with stent implantation was performed in 151 consecutive patients. The angioplasty was performed by a single cardiologist in the presence of a backup operator. Angioplasty and stent placement were successful in 151 of 153 cases (success rate = 98.7%). No death occurred and no case of acute stent occlusion was observed. In no case was the backup operator called for assistance. In conclusion, angioplasty with stent placement by a single operator without the assistance of a second interventional cardiologist or a specialized nurse was feasible, effective and safe . (J Interven Cardiol 2000;3-6)     

TWO-STAGE INFUSION OF ETOMIDATE FOR THE INDUCTION AND MAINTENANCE OF ANAESTHESIA

A two-stage infusion technique of etomidate with a separateinfusion of fentanyl was compared with thiopentone and halothaneor morphine, phis nitrous oxide in oxygen, for the inductionand maintenance of anaesthesia in 200 patients. Cardiovascularand respiratory indices and recovery times were found to besimilar in the two groups     

Natural History of Sinus Node Chronotropy in Paced Patients

The natural history of chronotropic incompetence is not clear. To assess this, we evaluated corrected sinus node recovery time (cSNRT) and sinus node chronotropy at rest and during exercise in two groups of syncopal patients with sinus node disease. Group A comprised patients with resting bradycardia but normal cSNRT and group B had resting bradycardia and prolonged cSNRT (> 1000 ms). An additional two groups (C and D) were studied. Group C comprised patients with complete AV (CAVB) and no evidence of sinus node disease and group D were asymptomatic controls of similar age. At diagnosis, patients with symptomatic bradycardia but normal cSNRT and no evidence of carotid sinus syndrome (group A) had resting bradycardia and impaired peak heart rate (PHR-I) on exercise compared to controls (P < 0.001 and P < 0.05, respectively), but no reduction in exercise duration. At follow-up group A patients demonstrated an increase in resting rate that was significantly slower than the controls (P < 0.01). Peak heart rate (PHR-II) also remained significantly slower (P < 0.05). There was no difference in exercise duration between groups A and D at follow-up. Group B was further subdivided according to follow-up findings of preservation of atrial activity in seven patients (group B-1) and junctional rhythm without any atrial activity in four patients (group B-2). Retrospective analysis showed no significant difference in resting heart rate at initial examination but group B-2 showed a significantly lower peak heart rate on exercise compared with B-1 (P < 0.01). Follow-up exercise tests revealed reduced exercise capacity in B-2 patients when compared with B-1 (P < 0.05) and both B-1 and B-2 had significantly reduced exercise capacity when compared with control groups C and D (P < 0.001). Group C patients had an initial sinus node chronotropic response to exercise, which was not different from control but significantly better (P < 0.01) than group B. At follow-up, the mean peak sinus rate of group C patients was unchanged, while there was an insignificant prolongation of cSNRT. Thus, patients with resting bradycardia, blunted peak heart rate response to exercise, and markedly prolonged CSNRT are those most likely to show chronotropic incompetence over the long-term and should be considered for rate responsive dual (or single) chamber pacing systems.