Association between clinical expression and molecular heterogeneity in ß-thalassemia Tunisian patients.

Beta-thalassemia is the most frequent hereditary blood disorder in Tunisia because of its geographic localization and history. This pathology is characterized by a complex multisystem process with genetic and biochemical interactions. The aim of this work was to establish phenotype/genotype association through studying the distribution and the relationship between ß-thalassemia and α-thalassemia mutations and three polymorphic markers: the C → T polymorphism at -158 of the Gγ gene, the RFLP haplotype and the repeated sequence (AT)xTy in the ß globin silencer, in two groups of ß-thalassemia major and ß-thalassemia intermedia (TI) patients. Statistical analysis has shown that moderate expression seen in TI patients was significantly associated to ß(+) -87 (C → G), -30 (T → A) and IVSI-6 (T → C) mutations, haplotypes VIII, IX and Nb and to XmnI polymorphism. The regression analysis of combined genotypes (mutation/XmnI/RFLP haplotype) revealed that they contribute to justify 17.1 % of clinical expression diversity (p < 0.05). Among the studied genotypes the XmnI polymorphism seems to be the most determinant modulating factor, followed by the ß-thalassemia mutation and RFLP haplotype. Our findings highlight the heterogeneity of molecular background of ß-thalassemia that would be responsible of clinical variability.

[Catecholaminergic polymorphic ventricular tachycardia in adult: a case report]. / La Tachycardie Ventriculaire Polymorphe Catécholergique Chez L'adulte : A Propos D'un Cas.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a primary electrical myocardial disease characterized by exercise- and stress-related ventricular lachycardia manifested as syncope and sudden death usually in child and teenager and was rarely described in adults. The management includes betablockade, with the use of implantable cardioverter defibrillators if medical treatment is insufficient. AIM: Report a new case of CPVT. OBSERVATION: We report a case of a 43 years old patient in whom CPVT diagnosis was made during his exploration for palpitations occurring with the effort. Registration Holter ECG revealed several episodes of supraventricular tachycardia and episodes of nocturnal sino-atrial block. The patient had an ICD and betablockade treatment. CONCLUSION: The TVPC in adult can manifest with attenuated symptoms that can be summarized with palpitations with the exertion. The supraventricular arrhythmias and sinus dysfunction may be at the forefront of Electrocardiographic manifestations. The prognosis of this form seems better than the TVPC of the child. Treatment with betablockade appears to be effective but existing dysfunction sinus facilitates decision to implant the ICD.

[Recovered sudden cardiac death associated with an early repolarization syndrome: case analysis and pratical aspects]. / Mort subite récupérée associée à un syndrome de repolarisation précoce: analyse d'un cas et attitude pratique.

In this article, we report the case of a 61-year-old man who presented a cardiac arrest which has been resuscitated successfully. An early repolarization syndrome has been diagnosed by the ECG recorded the first 3 days after admission. This abnormality disappeared after that. The patient received an implantable cardioverter-defibrillator. Practical messages to the clinician concerning early repolarization are provided in this article.

[Antiplatelet agents increase hemorrhagic risk in patients undergoing a cardiac pacemaker or ICD implantation]. / L'implantation des stimulateurs et défibrillateurs cardiaques sous antiagrégants plaquettaires augmente le risque hémorragique.

OBJECTIVES: This study was designed to assess the hypothesis that the implantation or the replacement of a cardiac stimulator or defibrillator in patients receiving antiplatelet agents is associated with an increase of the haemorrhagic risk in comparison with patients not receiving antiplatelet agents (control group). METHODS AND RESULTS: We retrospectively included all the patients undergoing pacemaker or ICD implantation or replacement between January 2007 and May 2010. The primary criterion was the incidence of bleeding complications. In our center, 685 patients were implanted in this period. Two hundred and fourteen (31%) were implanted while taking antiplatelet agents, including 164 (24%) taking aspirin, 31 (4%) taking clopidogrel and 19 (3%) taking the combination aspirin plus clopidogrel, while 471 patients (69%) did not receive antiplatelet agents. The primary criteria was the hemorrhagic complications. Complications were noted in 14 patients out of 471 (3%) not taking antiplatelet agents, in 16 patients out of 214 (7.5%) taking an antiplatelet agent (P=0.004). The complications concerned 13 patients out of 164 taking aspirin (7.9%), one patient out of 31 (3.2%) taking clopidogrel and two patients out of 19 taking the combination aspirin plus clopidogrel (10.5%) (P=0.042 for aspirin vs placebo, NS for all other comparisons). In multivariable analysis, the factors associated with an increase of the heamorrhagic complications were the type of implant (ICD) (OR 3,7; P=0.001) and antiplatelet treatment (OR 2,7; P=0.009). CONCLUSION: Pacemaker and ICD implantation or replacement in patients taking antiplatelet agents are associated with an increase of the hemorrhagic risk.

[Oral anticoagulation doesn't increase hemorrhagic risk in patients undergoing a cardiac pacemaker or defibrillator implantation]. / L'implantation des stimulateurs et défibrillateurs cardiaques sous antivitamines K n'augmente pas le risque hémorragique.

OBJECTIVES: This study was designed to assess the hypothesis that the implantation or the replacement of a cardiac stimulator or defibrillator in patients receiving oral anticoagulants with an INR≥2 doesn't increase the hemorrhagic risk in comparison with patients for whom the treatment has been interrupted temporarily (INR<2) or with patients not receiving anticoagulants (control group). PATIENTS AND RESULTS: We performed a retrospective chart review of bleeding complications in all patients undergoing pacemaker or ICD implantation or replacement between January 2007 and may 2009. In this cohort, 43 patients (10%) were implanted with an INR≥2 while 36 patients (8%) were implanted with an INR<2 and 352 patients (82%) didn't receive anticoagulants. No complication (0/36) has been observed in patients having an INR<2, while 3/43 (7%) complications have been observed in patients with an INR≥2 and 13/352 (3.7%) in patients in the control group (p=0.3093). Duration of the hospital stay was similar in the three groups: 6.2 days in patients with an INR<2, 6.8 days in the group with an INR≥2 and 6.2days in the control group (p=0.686). CONCLUSION: Pacemaker and ICD implantation or replacement without withdrawing of oral anticoagulants and an INR≥2 was not associated with an increase of the hemorrhagic risk.

[Hemorrhagic risk of different perioperative anticoagulation protocols in patients implanted with a cardiac pacemaker or defibrillator: retrospective analysis in patients implanted in a community hospital]. / Evaluation du risque hémorragique de différents protocoles d'anticoagulation péri-opératoire lors d'une primo-implantation ou un remplacement d'un stimulateur ou d'un défibrillateur cardiaque : analyse d'une cohorte de patients en centre hospitalier général.

AIMS: Perioperative management of anticoagulation in patients referred for pacemaker or cardiac defibrillator implantation isn't consensual. Our objective was to evaluate, in a large cohort, hemorrhagic complications in patients having implantation or replacement of a cardiac pacemaker or defibrillator, and to assess perioperative anticoagulation effect on hemorrhagic risk. METHODS AND RESULTS: A cohort of 461 consecutive patients having implantation or replacement of a cardiac pacemaker or defibrillator has been analyzed. Thirty patients (6,5%) had oral anticoagulants (OAC) switched to heparin/low-molecular-weight heparin, while 76 (16,5%) had their oral anticoagulation disrupted habitually for 48 hours. A total of six over 30 (20%) and two over 76 (2.6%) patients in the bridge and OAC, respectively experienced a pocket hematoma (bridge vs. OAC, p<0.05), while ten over 355 (2.8%) had a pocket hematoma in the control group (bridge vs. control p=0.006). Duration of the hospital stay was longer in the bridge group in comparison with OAC and control groups (9 vs. 7 vs. 6 days, respectively, p=0.006). CONCLUSION: Oral anticoagulation bridging with heparin or low-molecular-weight heparin is associated with a higher risk of pocket hematoma and a longer duration of hospitalization, in comparison with a strategy allowing a temporary disruption of OAC adapted to the thromboembolic risk.