Response to flecainide infusion predicts long-term success of hybrid pharmacologic and ablation therapy in patients with atrial fibrillation.

OBJECTIVES: We tested the hypothesis that the response to flecainide infusion can identify patients with atrial fibrillation (AF) in whom the hybrid pharmacologic and ablation therapy reduces the recurrences of AF. BACKGROUND: Infusion of class IC anti-arrhythmic drugs may promote transformation of AF into atrial flutter. Catheter ablation of atrial flutter has been demonstrated to be highly effective in preventing recurrences of atrial flutter. METHODS: Seventy-one consecutive patients with paroxysmal or chronic AF, in whom flecainide infusion (2 mg/kg body weight, intravenously) determined the transformation of AF into common atrial flutter (positive response), were randomized to receive one of the following treatments: oral pharmacologic treatment with flecainide (group A, n = 23); the hybrid treatment (catheter ablation of the inferior vena cava-tricuspid annulus isthmus, plus oral flecainide) (group B, n = 24); or catheter ablation of the isthmus only (group C, n = 24). Thirty-seven patients with a negative response to flecainide, who chose to be submitted to the hybrid treatment, were selected as the control group (group D). RESULTS: During a mean follow-up period of 24 +/- 7.2 months, the recurrences of AF and atrial flutter in group B (42%) were significantly lower than those in group A (78%, p < 0.001), group C (92%, p < 0.001) and group D (92%, p < 0.001). CONCLUSIONS: The creation of a complete bi-directional conduction block at the inferior vena cava-tricuspid annulus isthmus, plus flecainide administration, reduces the recurrences of both AF and atrial flutter in patients with class IC atrial flutter. Moreover, the early response to flecainide is safe and reliable in identifying patients who may benefit from this therapy.

Pretreatment with verapamil in patients with persistent or chronic atrial fibrillation who underwent electrical cardioversion.

OBJECTIVES: To evaluate, in a prospective and randomized fashion, the efficacy of a pretreatment with verapamil (V) in reducing recurrences of atrial fibrillation (AF) after electrical cardioversion (C). BACKGROUND: The increased vulnerability for AF recurrence is probably due to AF-induced changes in the electrophysiologic properties of the atria. This electrical remodeling seems to be due to intracellular calcium overload. METHODS: One hundred seven patients with persistent or chronic AF underwent external and/or internal C. All patients received oral propafenone (P) (900 mg/day) three days before and during the entire period of follow-up (three months). In the first group, patients received only the P. In the second group, in adjunct to P, oral V (240 mg/day) was initiated three days before C and continued during the follow-up. Finally, in the third group, oral V was administered three days before and continued only for three days after electrical C. RESULTS: During the three months of follow-up, 23 patients (23.7%) had AF recurrence. Mantel-Haenszel cumulative chi-square reached a significant level only when comparing AF free survival curves of group I versus group II and group III (chi-square = 5.2 and 4, respectively; p < 0.05). Significantly, 15 (65.2%) AF relapses occurred during the first week after cardioversion with a higher incidence in group I (10/33 patients, 30.3%) than group II (2/34 patients, 5.9%; p = 0.01) and group III (3/30 patients, 10%; p = 0.04). CONCLUSIONS: Six days of oral V administration centered on the C day, combined with P, significantly reduce the incidence of early recurrences of AF compared with P alone.

[The predictive value of junctional beats during the radiofrequency transcatheter ablation of the slow pathway of the nodal reentry circuit]. / Valore predittivo dei battiti giunzionali durante l'ablazione transcatetere mediante radiofrequenza della via lenta del circuito di rientro nodale.

BACKGROUND: Junctional beats (JB) are often recorded during slow pathway (SP) radiofrequency (RF) ablation in patients with atrioventricular nodal reentrant tachycardia (AVNRT). Neither the correlation between JBs and SP potentials nor the role of mechanically-evoked JBs has been clarified yet. METHODS: Two hundred-eleven consecutive patients, with common AVNRT, underwent RF transcatheter ablation guided by Jackman SP potential searching. If we were unable to record an SP potential or if 4 RF pulses delivered on ideal ablation sites were ineffective, the ablation was carried out on anatomical landmarks. Light pressure was applied with the ablation catheter to each ablation site before RF delivery in order to evaluate the inducibility of JBs. RESULTS: Transcatheter ablation was performed successfully in 209/211 (99%) patients. In 17 (8.1%) patients, no SP potential was recorded. JBs were observed more often delivering RF in the mid-septal region, whereas SP potentials were more often recorded at the base of the Koch triangle. The success rate (successful pulses/overall pulses) was higher in the mid-septal (58.6% in M1, 77.8% in M2) than in the postero-septal region (4% in PSC, 16.8% in P1). JBs showed a higher specificity (73.2 vs 5.3%), positive (55.5 vs 24.6%) and negative predictive value (97.3 vs 63.8%) than SP potential in identifying the successful ablation site. Mechanical JBs were evoked in 23 patients on 29 ablation sites, and 18/29 (62.1%) of them were successful ablation sites. CONCLUSIONS: The recording of JBs during or before RF ablation is a useful parameter to guide SP ablation in patients with AVNRT. Although the underlying mechanism has not been clarified yet, their preferential occurrence in the mid-septal region suggests that they might be due to thermal stimulation of compact atrioventricular node.

[Evaluation of the function of heart valve prostheses by Doppler echocardiography. Primary findings]. / Valutazione della funzionalità delle protesi valvolari mediante l'impiego dell'ecocardiografia con effetto Doppler. Prime considerazioni.

The authors have executed an investigation on the functional evaluation of the valvular prosthesis, availing themselves of the use of the Echocardiography complete of Doppler effect and executing echocardiography tracings not according to the standard position, but putting the sound in correspondence with the cardiac apex. This method has been considered valid to obtain olways images of the movable element for all the types of the prosthesis and for amy situation of theirs. Furthermore the classic position of the sound can't be respected either for the eventual cardiomegaly, either for the manipulations that the heart undergoes inevitable during the operation, either for the pleurapericardic adhesions, alla factors that induce a change of the anatomic focuses.

[Cardiac muscle malacia as the factor inhibiting myocardiac electric stimulation, as seen in echocardiographic examination]. / La malacia del muscolo cardiaco quale fattore inibente l'elettrostimolazione miocardica, vista all'esame ecocardiografico.

In this present research work the Authors think that a preliminary echocardiography study may be useful to evoluate the type of answer of the cardiac muscle to the artificial stimulus; they deem, forthmore, thot, among the ecocardiografic obtainable parameters the principle importance must be attributed to the velocity of contraction of the circumference fibres (Vef) and to the velocity of the motion of the back wall in a sistolic phase the cases like the one mentioned in the text, with marked reduction of the motion and with Vef of 0.25 circ./sec, according to the Authors can't be stimulated through the employment of a stimulating endocavitle catheter, but they require, for a sure stimulation, the application of the epicardic electrodes.

[Prevention of arrhythmias during heart catheterization]. / Profilassi delle aritmie in corso di cateterismo cardiaco

The utility of using beta blocking drugs, specifically Pindolol, as a prophylaxis for arrhythmia during cardiac microcatheterism according to Grandjean's technique has been observed. The drug is even more useful when it is considered that it does not affect dp/dt value.

[Complete polygraphic examination using the Diamont and Killip calculations in the functional evaluation of the heart patient]. / L'esame poligrafico integrato con i calcoli di Diamont e Killip nella valutazione funzionale del cardiopatico

Recently discharged infarct patients were examined to assess their ability to rehabilitate. This led to the elaboration of a classification based on polygraphic parameters, rather than the history and clinical record, coupled with comparison with the ideal values given for such subjects by the formula of Diamont and Killip.

[Value of the esophageal ECG]. / Considerazioni sull'utilità dell'ECG esofageo

The Authors examined 20 patients suffering from anginose symdrome, whose standard ECG did not show remarkable alterations. In the same patients, oesophagus ECG did show clear signs of sub-epicardium lesion as well as necrosis, which interested the upper part of left ventricle's posterior wall; such zone is not explorable by traditional ECG. Hemodynamic poligraphic examinations were made as well, and thus also a reduction of cardiac inotropism was found out.