Atrial late potentials in patients with paroxysmal atrial fibrillation detected using a high gain, signal-averaged esophageal lead.

High gain, signal-averaged ECGs using conventional surface lead technique and a transesophageal lead technique were performed in 45 idiopathic paroxysmal atrial fibrillation patients and in 33 normal controls. Both techniques showed increased P wave duration in patients compared with the controls (P < 0.001), but higher P wave amplitudes were obtained using the transesophageal technique compared with surface leads (patients: 169.8 +/- 81.7 microV vs 15.8 +/- 7.3 microV; P < 0.0005; controls: 163.5 +/- 22.1 microV vs 18.5 +/- 5.2 microV; P < 0.0005). The signal-averaged transesophageal lead, but not the surface recordings, identified the presence of atrial late potentials evidenced by lower root mean square voltages in the terminal portion of the P wave: in last 10 seconds, 4.4 +/- 1.3 microV versus 8.5 +/- 3.0 microV; P < 0.001; in last 20 seconds, 7.0 +/- 2.3 microV versus 16.0 +/- 7.9 microV; P < 0.001; in last 30 seconds, 12.5 +/- 5.3 microV versus 23.8 +/- 12.8 microV; P < 0.001, in patients with respect to controls. The criterion P wave duration > or = 110 msec had 85% sensitivity, 100% specificity, and 100% positive predictive value in identifying the patients; the combined criteria P wave duration > or = 110 msec and root mean square for the last 10 msec < or = 6.5 showed 80% sensitivity, 100% specificity, and 100% predictive value. The signal-averaged transesophageal lead produces a higher amplitude signal, which reveals fractionation of atrial activation in atrial fibrillation and allows identification of individuals predisposed to this arrhythmia.

[The high-resolution analysis of the P wave recorded via the esophagus: a new diagnostic approach in patients with paroxysmal atrial fibrillation]. / L'analisi ad alta risoluzione dell'onda P registrata per via transesofagea: nuovo approccio diagnostico in pazienti con fibrillazione atriale parossistica.

BACKGROUND: P-wave signal averaged ECG has recently been proposed in the evaluation of patients with Paroxysmal Atrial Fibrillation (PAF). The aim of this study was to verify the utility of this method in the characterisation of these patients utilizing a transoesophageal signal. METHODS: The study population consisted of two groups of subjects: Group A, 34 consecutive patients (16 males; 57 +/- 9 yrs) with a documented PAF and without any underlying heart disease, and Group B, normal controls (9 males; 44 +/- 6 yrs). A signal-averaged ECG, triggered with the oesophageal P-wave, obtained from an X, Y, Z lead system was recorded in each patient, utilizing the AEROTEL HIPEC 200 system. The three orthogonal averaged ECGs were band-pass filtered (non-recursive filter, 40-250 Hz) and combined into a spatial vector magnitudo. We evaluated the filtered P-wave duration (Ad, msec) and the Root Mean Square (RMS) voltages of the last 10, 20, and 30 msec of the P vector magnitudo (RMS 10, 20, 30; mcV). RESULTS: The patients with PAF presented with a significantly longer Ad duration (A 126.6 +/- 12.4 vs B 96.8 +/- 12.5 msec, < 0.001), and lower amplitudes of RMS 10, 20, 30 (RMS 10 A 4.8 +/- vs B 9 +/- 2.7 p < 0.005; RMS 20 A 6.9 +/- 2.3 vs B 15.7 +/- 7.3 p < 0.005; RMS30 A 12.1 +/- 5.1 vs B 25.3 +/- 11.5 p < 0.005). An Ad > or = 100 msec, a value of RMS 10 < or = 6.5, RMS 20 < or = 9 and RMS 30 < or = 12.5 mcV showed high values of sensitivity, specificity and positive predictive value (Ad 85%, 100%, 100%, RMS10 93%, 80%, 90%, RMS20 84%, 90%, 96%, RMS30 72%, 90%, 72%). The combined duration/voltage criteria (Ad +/- 110 msec and RMS10 < or = 6.5 mcV or RMS20 < or = 9 mcV) showed a sensitivity of 80% and 76% with a specificity and positive predictive value of 100%. CONCLUSIONS: The P-wave triggered transoesophageal atrial signal averaged ECG appears able to identify patients with PAF; however, prospective studies must investigate the possible clinical use of these findings.

[The efficacy of oral treatment with flecainide for paroxysmal atrial fibrillation: correlation with plasma concentration]. / Efficacia del trattamento orale con flecainide nella fibrillazione atriale parossistica: correlazione con le concentrazioni plasmatiche.

In the acute treatment of paroxysmal atrial fibrillation several drugs can be used. The aim of our work was to assess the efficacy of a single oral dose of flecainide in the conversion to sinus rhythm by correlating this data with flecainide plasma concentration. We have considered 37 patients affected by paroxysmal atrial fibrillation (for more than 8 hours) randomly assigned to the following two groups: group A, 19 patients, mean age 44.4 +/- 1.9 years) treated with flecainide (200 mg) and control group B (18 patients, mean age 46.6 +/- 1.8 years). This was done in order to point out any possible overlap between pharmacological and spontaneous conversion to sinus rhythm. In all patients, the following were performed: a Holter recording (524 hours) to evaluate the time of conversion to sinus rhythm (t-conversion to sinus rhythm), a determination of flecainide plasma concentration (after 150 flecainide administration) an Rx, an Echo-2D/Doppler test and an estimation of thyroid function. The Rx, the Echo-2D/Doppler and the endocrinological data in the 2 groups did not show any significant differences. We obtained a conversion to sinus rhythm in all but one of the group A patients (time of conversion to sinus rhythm 162 +/- 83 min) and in just 5 group B patients (time of conversion to sinus rhythm 1118 +/- 125 min) (time of conversion to sinus rhythm A vs B p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Early peak of CPK in acute myocardial infarct: a marker of clinical instability?]. / II picco precoce della CPK in corso di IMA: marker di instabilità clinica?

The evaluation of the CPK-peak time (CPK-p) during Acute Myocardial Infarction (AMI) is now considered as a reliable method to identify ischemic myocardial tissue reperfusion both spontaneous and pharmacologically-induced. The purpose of this study is to assess the clinical significance of this index over a non selected group of patients (pts) affected by a first episode of AMI looking for some variables possibly connected with it. This study includes 114 pts hospitalized in our Unit Coronary Care (UCC) and diagnosed as affected by AMI and not treated with anticoagulant and/or fibrinolytic drugs. They were divided according to CPK-p into 2 groups: group A (23 pts, 18M 5F, mean age 64.2 +/- 10.1y; CPK-p 11.9 +/- 3.3h, AMI Anterior 14/AMI Inferior 9) and group B (91 pts, 85M 6F, mean age 64 +/- 10.3y; CPK-p 25.7 +/- 4.5h, AMI Anterior 50/AMI Inferior 41). Moreover, a third group C has been studied including pts with similar clinical characteristics who underwent thrombolysis by intravenous infusion of Streptokinase (48 pts, 39M 9F, mean age 62.7 +/- 10.6y; CPK-p 15.2 +/- 7h, AMI Anterior 28/AMI Inferior 20). For each pt CKP-p has been evaluated as well as the pre-UCC time (T-pc), the maximum value of released CPK (CPK-max), the incidence of new coronary events such as angina, re-AMI, sudden death detected between the 1st (NEC-I) and the 6th month (NEC-II) after the acute event.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitored long-term treatment with ibopamine in patients suffering from severe congestive heart failure.

50 patients with congestive heart failure underwent monitored long-term treatment aimed at evaluating the effect of ibopamine (SB-7505), the 3,4-diisobutyryl ester of N-methyldopamine, on their condition. Ibopamine was administered alone or in combination with traditional therapy mainly at a dose of 100 mg t.i.d. Clinical scores and NYHA (New York Heart Association) functional classes improved. Biochemical parameters showed no adverse modifications. Mild transient side-effects probably related to ibopamine occurred in two patients.