Pan pneumo: an unusual complication following pacemaker implantation.

Implantation of cardiac devices is usually considered to be a safe procedure. Rare complications, such as pneumothorax, may occur after the procedure. The association with pneumopericardium or pneumomediastinum is even more uncommon. We present the case of a patient in his 70s, on haemodialysis, admitted for complete atrioventricular block. He underwent implantation of a dual-chamber pacemaker. He presented with chest pain the day after implantation. Chest CT scan revealed a pneumothorax associated with a pneumopericardium and pneumomediastinum 'pan pneumo', due to an atrial perforation. We opted for a conservative management strategy. Repeat CT scan of the chest 8 days after the procedure showed a complete resorption of the 'pan pneumo'. The objective of this case report is to describe this rare complication and provide further insight into its management, particularly in the absence of specific guidelines.

Dobutamine Stress Echocardiography Unmasks Early Left Ventricular Dysfunction in Asymptomatic Patients with Uncomplicated Type 2 Diabetes: A Comprehensive Two-Dimensional Speckle-Tracking Imaging Study.

BACKGROUND: Discrepancies are present in the literature on resting myocardial mechanics in patients with uncomplicated type 2 diabetes mellitus (T2DM). Data are noticeably sparse regarding circumferential function and torsional mechanics. Resting deformation imaging may not be sensitive enough to detect subtle dysfunctions. The aim of this study was thus to comprehensively evaluate myocardial mechanics in patients with T2DM at rest and to investigate whether dobutamine stress echocardiography could unmask functional alterations that would remain otherwise subtle at rest. METHODS: Forty-four patients with T2DM and 35 healthy control subjects of similar age and sex were prospectively recruited. After conventional echocardiography, myocardial mechanics was evaluated at rest and during low-dose dobutamine stress echocardiography (target heart rate, 110 beats/min). RESULTS: Patients with T2DM presented with altered global diastolic function but preserved systolic function. Deformation imaging indexes were similar between groups at rest, but significant differences were noticed under dobutamine infusion for longitudinal strain (-21.2 ± 2.4% vs -24.2 ± 2.5%, P < .001), circumferential strain (apex, -32.3 ± 5.3% vs -36.3 ± 5.3%, P = .002; papillary muscle, -25.6 ± 3.2% vs -28.0 ± 3.6%, P = .001; base, -23.2 ± 3.6% vs -25.3 ± 3.8%, P = .03), apical (11.2 ± 4.4° vs 14.1 ± 6.3°, P = .020) and basal (-12.2 ± 3.3° vs -14.3 ± 3.9°, P = .021) rotation, and twist (21.9 ± 5.9° vs 26.8 ± 8.3°, P = .007). Multivariate analysis identified epicardial fat, dyslipidemia, and fasting glycaemia as significant contributors to the changes from rest to dobutamine. CONCLUSIONS: These findings demonstrate the usefulness of dobutamine stress echocardiography in establishing impairments in myocardial mechanics in patients with uncomplicated T2DM. Systemic metabolic disturbances and epicardial fat act as the main contributors to the blunted response to dobutamine stress in these patients.

[Cardiac resynchronisation]. / La resynchronisation cardiaque.

A fifth of patients with heart failure suffer from conduction disorders. A prolonged QRS duration on the electrocardiogram is an indicator of cardiac dyssynchrony. Several studies have shown the efficacy of cardiac resynchronisation therapy (CRT) in patients with a wide QRS duration: CRT is associated with reduced morbidity and mortality. An overview of the methods of implantation of CRT devices, the results of this electrical treatment and its limits.

Permanent left atrial pacing therapy may improve symptoms in heart failure patients with preserved ejection fraction and atrial dyssynchrony: a pilot study prior to a national clinical research programme.

AIMS: Our group has recently shown that in some patients, heart failure with preserved ejection fraction (HFPEF) may be explained by 'atrial dyssynchrony syndrome' (ADS) due to interatrial conduction delay (IACD), a short left atrioventricular interval (LAVI), and increased left atrial (LA) stiffness. Our primary objective was to evaluate LA pacing therapy as a new treatment to restore left ventricular active filling in patients with no other known causes for HF than ADS. METHODS AND RESULTS: Six patients with severe HFPEF with IACD (P wave duration >120 ms in lead II), short LAVI during electrophysiological studies (<70 ms), a restrictive filling pattern (E/e' >15), and no standard indication for a pacemaker were implanted with a lead screwed inside the coronary sinus for active LA pacing. After 3 months of active pacing, a 2 week randomized double-blind crossover phase compared active vs. inactive LA pacing. After 3 months of pacing, the mean distance walked in 6 min (6MWD) was 21% greater (240 ± 25 m vs. 190 ± 15m, P < 0.05), mitral A wave duration was longer (104 ± 8 vs. 158 ± 25 ms, P = 0.002), and E/A and E/e' ratios were smaller (3.4 ± 1.3 vs. 1.8 ± 0.9, P = 0.009, and 22.6 ± 4.6 vs. 15.3 ± 4.3, P = 0.006, respectively). Inactivation of pacing for 1 week led to a significant reduction in the 6MWD, with an on/off response. CONCLUSION: The beneficial effects of LA pacing observed in this pilot study will have to be confirmed by the randomized, controlled crossover 'LEAD' study.

Multifocal ectopic Purkinje-related premature contractions: a new SCN5A-related cardiac channelopathy.

OBJECTIVES: The aim of this study was to describe a new familial cardiac phenotype and to elucidate the electrophysiological mechanism responsible for the disease. BACKGROUND: Mutations in several genes encoding ion channels, especially SCN5A, have emerged as the basis for a variety of inherited cardiac arrhythmias. METHODS: Three unrelated families comprising 21 individuals affected by multifocal ectopic Purkinje-related premature contractions (MEPPC) characterized by narrow junctional and rare sinus beats competing with numerous premature ventricular contractions with right and/or left bundle branch block patterns were identified. RESULTS: Dilated cardiomyopathy was identified in 6 patients, atrial arrhythmias were detected in 9 patients, and sudden death was reported in 5 individuals. Invasive electrophysiological studies demonstrated that premature ventricular complexes originated from the Purkinje tissue. Hydroquinidine treatment dramatically decreased the number of premature ventricular complexes. It normalized the contractile function in 2 patients. All the affected subjects carried the c.665G>A transition in the SCN5A gene. Patch-clamp studies of resulting p.Arg222Gln (R222Q) Nav1.5 revealed a net gain of function of the sodium channel, leading, in silico, to incomplete repolarization in Purkinje cells responsible for premature ventricular action potentials. In vitro and in silico studies recapitulated the normalization of the ventricular action potentials in the presence of quinidine. CONCLUSIONS: A new SCN5A-related cardiac syndrome, MEPPC, was identified. The SCN5A mutation leads to a gain of function of the sodium channel responsible for hyperexcitability of the fascicular-Purkinje system. The MEPPC syndrome is responsive to hydroquinidine.

Atrial dyssynchrony syndrome: an overlooked phenomenon and a potential cause of 'diastolic' heart failure.

AIMS: The purpose of the present study was too explore the role of interatrial dyssynchrony in heart failure with preserved ejection fraction (HFPEF). METHODS AND RESULTS: For the case study we selected seven patients with severe HFPEF, with interatrial block on electrocardiogram (ECG), and a delayed and interrupted A wave on mitral Doppler. Echocardiographic left atrial (LA) volumes/functions, mitral E/A and E/e' ratios, mitral A wave duration/deceleration time, and interatrial mechanical delays (IAMDs) at tissue Doppler, were studied. We performed right heart catheterization, and an electrophysiological study (EPS) for the measurement of interatrial conduction delay (IACD) and left atrioventricular interval (LAVI). Mean IAMD was 106 ms. All the patients exhibited a restrictive mitral Doppler pattern, high E/A and E/e' ratios, and short A wave duration/deceleration time. Left atrial volume was increased, with severely depressed functions. Right heart catheterization showed severe post-capillary pulmonary hypertension. The EPS showed an IACD of 170 ± 20 ms, with a short LAVI. Left atrial pacing through the coronary sinus reduced the IACD to 25 ± 15 ms. In the pilot study, 29 patients with HFPEF were compared with 27 age-matched control patients. HFPEF patients had longer P waves, shorter A waves, and a longer IAMD than the controls. Prevalence of severe IAMD >60 ms was 59% in HFPEF and 0% in controls. In the HFPEF group, patients with an IAMD >60 ms had significantly shorter A waves and higher E/e' ratio. CONCLUSION: Some HFPEF patients present with IACD, delayed LA systole, shortened LA emptying, decreased LA compliance, and increased filling pressures. Whether the condition of these patients could be improved by atrial resynchronization deserves further investigation.

Functional analysis reveals splicing mutations of the CASQ2 gene in patients with CPVT: implication for genetic counselling and clinical management.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and severe arrhythmogenic disorder. Although usually transmitted in a recessive form, few cases of dominant mutations have been reported. Thirteen mutations in the CASQ2 gene have been reported so far in association with CPVT. We performed molecular analysis of the CASQ2 gene in 43 probands with CPVT and identified eight mutations in five patients. Six mutations were novel: one was a single nucleotide deletion, three affected consensus splice sites, and two had unknown consequences: the c.939 + 5G>C and the synonymous c.381C>T variations. We demonstrated that these two variations affected CASQ2 splicing using a splicing minigene assay. These data increased significantly the number of CASQ2 mutations described in association with CPVT, revealed the high prevalence of splicing and truncating mutations in this gene and brought new insight regarding the dominant inheritance of the disease. Moreover, our report of the first splicing abnormalities in CASQ2 caused by intronic mutation or synonymous change underlines the absolute necessity to perform extensive molecular analysis for genetic diagnosis and counseling of CPVT.

Increased superoxide anion production is associated with early atherosclerosis and cardiovascular dysfunctions in a rabbit model.

OBJECTIVE: Hypercholesterolemia (HC) has been associated with impairment of vascular and myocardial functions. As HC could generate an alteration in the oxidative status, we studied the effects of a 1-month cholesterol diet on cardiovascular oxidative stress. METHODS AND RESULTS: New Zealand rabbits received cholesterol (1%) or normal chow for 1 month. At 30 days, superoxide anion levels, assessed by ESR spectroscopy, NAD(P)H oxidase (NOX) activity, and dihydroethidium (DHE) staining of aortas were higher in the cholesterol-fed (CF) group compared with control (respectively, 4.0 +/- 0.6 Arbitrary Units/mg (AU/mg) vs. 2.6 +/- 0.3, p < 0.05; 4231 +/- 433 vs. 2931 +/- 373 AU/mg, p<0.05; 21.4 +/- 1.2 vs. 12.9 +/- 1.7% fluorescence/mm2, p < 0.001). NOX gp91 phox and p67 phox expression in the aortas were higher in the CF group vs. control (1.5 +/- 0.2 vs. 0.5 +/- 0.2, p < 0.001; 0.9 +/- 0.2 vs. 0.3 +/- 0.2, p<0.05). The endothelium-dependent relaxation evaluated on the iliac arteries was higher in control than in the CF group (64.8 +/- 10.1 vs. 13.1 +/- 3.70%, p<0.001). The cardiac diastolic pressure estimated on isolated hearts was higher in the CF group than in control (21.1 +/- 4.1 vs. 10.3 +/- 1.4 mmHg, p<0.05) after 60 min of ischemia. CONCLUSIONS: Hypercholesterolemia induced increased levels of superoxide in the aortas and a higher expression of NOX subunits, associated with altered vasorelaxation. The increased diastolic pressure observed in hearts, consistent with a post-ischemic contractile dysfunction might be mediated by the production of superoxide.

Factors affecting the management of outcome in elderly patients with acute myocardial infarction particularly with regard to reperfusion. Data from the French regional RICO survey.

BACKGROUND: Acute myocardial infarction (AMI) in elderly patients is often unrecognized and associated with poor prognosis. OBJECTIVES: To investigate management and efficacy of reperfusion therapy to the elderly patients with AMI. METHODS: From the January 1, 2001 to October 31, 2002, 964 patients with AMI were included in the French regional RICO survey. The patients were divided into three groups: younger (<70 years old), elderly (70-79 years old) and very elderly (>or=80 years old). RESULTS: Distribution of groups was 56, 27, and 16%, respectively. The longest time delay to first request for medical attention was found in the very elderly group (30 and 55 vs. 90 min, respectively, p < 0.05). Rate of lysis fell significantly with increasing age (35, 22 and 9%, respectively, p < 0.001) but the time delay to lysis was similar for the 3 groups. The proportion of patients who benefited from primary percutaneaous transluminal coronary angioplasty decreased with age (21, 15, 11%, respectively, p < 0.001), but time delay to balloon angioplasty was similar and no difference in mortality rate was observed between the three groups after reperfusion. The incidence of in-hospital cardiovascular events (cardiogenic shock and recurrent myocardial infarction/ischemia) and in-hospital mortality increased with age (5, 13, 17%, respectively, p < 0.001). Moreover, multivariate analysis showed that only ejection fraction and Killip >1 were independent predictive factors for in-hospital cardiovascular mortality, respectively (OR 5.15, 95% CI 2.08-12.74, p < 0.0001 and OR 3.81, 95% CI 1.90-7.65, p < 0.0001), whereas age, sex, diabetes and anterior location were not significant. CONCLUSION: Our data in an unselected population indicate that very elderly patients were characterized by increased pre-hospital delays and less frequent utilization of reperfusion therapy, although no difference in the mortality in reperfused patients could be observed between the three age groups.