Persistent Atrial Fibrillation And Atrial Flutter Complicated By Tachycardiomyopathy Because Of Intermittent Conduction Through Accessory Pathway.

The term tachycardiomyopathy refers to a specific form of tachycardia-related cardiomyopathy caused by supraventricular or ventricular tachyarrhytmias that are both associated with ventricular rates higher than 120 bpm. The arrhythmias which are most frequently associated with these forms of heart disease are atrial fibrillation and atrial flutter, particularly found in the elderly population. The most frequent clinical manifestation is heart failure. In this case we are reporting a clinical case of a patient that came to our attention because of an episode of heart failure associated with atrial fibrillation and atrial flutter. The patient had also prolonged and repetitive strips of rapid conduction with wide QRS morphology. We don't know if the cause is pre excitation or ectopia. We showed that those strips of tachycardia with wide QRS, particularly when they were associated with atrial flutter, were so fast and consistent to determine the left ventricular contractile dysfunction; we showed also that those strips of wide complex tachycardia were caused by pre-excitation through an accessory right posteroseptal pathway and supported by the reentry circuit of common atrial flutter. The block of conduction through the accessory pathway and the elimination of atrial arrhythmia allowed the regression of left ventricular contractile dysfunction. We believe that this case is interesting because it shows that there is a strict continuity between sophisticated electrophysiological mechanisms and clinical manifestation.

[Natriuretic peptides and the heart. Critical review and application]. / Peptidi natriuretici e cuore. Revisione critica ed applicazioni.

This paper deals with a literature survey on natriuretic peptides (NP) and their clinical use in prognostic stratification and therapy of arterial hypertension and cardiac failure. After a brief historical introduction, the phylogenesis of NP is analyzed and the reasons of their preservation in the evolution are emphasized. The biochemistry of the NP is then treated, and the structure, synthesis, mechanism of cellular action and systems of regulation are analyzed. Subsequently, the authors have analyzed the physiology of the NP as well as their hemodynamic and biohumoral effects and actions on the central nervous system. A literature review on the significance of NP in arterial hypertension, on their usefulness as indicators of damage and on their therapeutic practice is then made. In particular, the possible future applications in the prevention of atherosclerotic damage are analyzed. The significance of NP and of their metabolites in heart failure and the prognostic implication of these peptides particularly in ischemic heart failure are then discussed. The most important papers on this topic are described. Finally the studies on the use of NP in the therapy of heart failure are analyzed and a guide on research of this topic is defined.

[Transesophageal echocardiography in patients with atrial fibrillation, candidates for cardioversion: usefulness and limitations]. / L'ecocardiografia transesofagea nei pazienti in fibrillazione atriale candidati a cardioversione: utilità e limiti.

BACKGROUND: Thromboembolic complications after electrical cardioversion (CV) of atrial fibrillation (AF) have been attributed to the dislodgment of preexistent left atrial thrombus during the resumption of atrial contraction. Transesophageal echocardiography (TEE) has been used to identify patients without thrombus, who potentially could undergo CV without anticoagulation. However, embolic events after CV in patients without evidence of thrombus on TEE have recently been reported. AIM OF THE STUDY: To evaluate if absence of thrombi or prethrombotic conditions such as spontaneous echo contrast or left atrial appendage disfunction can justify electrical CV without anticoagulant therapy. METHODS: Seventy-four patients with AF and candidates for CV underwent monoplane TEE. Patients were cardioverted without anticoagulation in case of: 1) absence of thrombus and/or spontaneous echocardiographic contrast and 2) good visualization of left atrial appendage, with a well defined peak blood flow velocity greater than 20 cm/sec. In all other cases, patients underwent anticoagulant therapy which started 3 weeks before CV and continued for 4 weeks afterwards. RESULTS: Forty-six patients, without thrombus or "prethrombotic" conditions, did not receive anticoagulation, while 28 followed traditional therapy with warfarin. Four patients with a thrombus in the left atrial appendage were identified: 1 died of cerebral embolism 3 days after the beginning of anticoagulation, in another one CV was definitely deferred because of the persistence of thrombus after 1 month of warfarin therapy. One patient, with left atrial appendage disfunction, died suddenly after 5 days of anticoagulation. Two patients reverted spontaneously in sinus rhythm. Two patients refused electrical CV. The remaining 67 patients underwent electrical CV which was successful in 56 of them. Cerebral embolism occurred 24 hours after CV in one patient who did not receive anticoagulation. Repeat TEE soon after embolism showed absence of thrombus or spontaneous echo contrast, but the presence of low flow velocity in the left atrial appendage. CONCLUSIONS: In patients in AF candidates for CV, exclusion of thrombi or prethrombotic conditions by TEE does not exclude the risk of thromboembolic events and the need for anticoagulant therapy. Left atrial appendage function can be stunned or impaired immediately after CV, favouring a thrombogenic milieu and subsequent embolic events. Therapeutic anticoagulation at the time of as well as after cardioversion is actually recommended.