[Usefulness of width and amplitude of P wave for prognosis of the efficacy of atrial sensing in patients with an implanted VDD pacemaker]. / Przydatnosc czasu trwania i amplitudy zalamka P w przewidywaniu skutecznosci sterowania przedsionkowego u chorych z implantowanym rozrusznikem VDD.

UNLABELLED: VDD stimulation is accepted as alternative mode of cardiac pacing to DDD in patients with atrio-ventricular (AV) conduction block and preserved sinus node function (SA). AIM OF THE STUDY: An attempt has been made to determine the relationship between width and amplitude of the P wave obtained during assessment the patient for the implantation procedure and the effectiveness of AV synchronization (PAS). MATERIAL AND METHODS: The study involved a group of 65 patients (43 male, 22 female), aged 66.6 +/- 12.7 with clinically significant disturbances of AV conduction, who did not reveal symptoms of concomitant disturbance in SA node automaticity. The width and amplitude of the P wave of the surface ECG were studied prior to the implantation procedure. Follow-up was carried out 3-4 days and 1, 3, 6 and 12 months after the procedure. The effectiveness of PAS was estimated by event counter read-out. RESULTS: Over the 12-month follow-up, the average value of the PAS coefficient was 95% for the entire group of patients. In 74% (subgroup A) synchronization was highly effective (PAS > or = 95%); in the remaining 26% (subgroup B) PAS occasionally fell below 95%. A statistically significant correlation between the width of the P wave of the surface ECG and the effectiveness of PAS was clearly demonstrated. In subgroup B, P wave was longer than in subgroup A (105 +/- 16 vs. 94 +/- 14 ms; p < 0.005). The width of P wave above 100 ms was the cutoff value of the ROC curve predicting PAS < 95%. CONCLUSIONS: The width of P wave obtained from surface ECG is correlated with effective AV synchronization. The value above 100 ms was predisposed to atrial undersensing.

Usefulness of electrocardiographic and echocardiographic parameters for predicting the efficacy of atrioventricular synchronisation during a single lead VDD/R pacing.

BACKGROUND: The VDD/R pacing is accepted as an alternative to DDD/R pacing in patients with atrioventricular conduction block (AVB) and intact sinus node function. AIM: To determine the relationship between parameters obtained during assessment of the patient for the implantation procedure, using electrocardiographic (ECG) and echocardiographic (ECHO) data, and the effectiveness of AV synchronisation. METHODS: The study involved a group of 65 patients (43 males, 22 females), aged 66.6 + 12.7 with clinically significant disturbances of AV conduction, who did not reveal symptoms of concomitant abnormalities in sinus node automaticity. Selected ECG and ECHO parameters were studied prior to the implantation procedure. Repeat examinations were done at 3-4 days and at 1, 3, 6 and 12 months after the procedure. The effectiveness of AV synchronisation (PAS) has been estimated by event counter read-out and ECG Holter monitoring. RESULTS: In 74% patients (subgroup A) synchronisation was highly effective (PAS _ 95%); in the remaining 26% subjects (subgroup B) PAS occasionally fell below 95%. In subgroup B, the P wave was longer than that in subgroup A (105 +/- 16 vs. 92 _ 13 ms; p < 0.05). The dimensions of the right and left heart chambers were greater in subgroup B. Patients in subgroup B had lower ejection fraction (49.4 +/- 13.7% in B vs. 58.2 +/- 11.3% in A) and revealed symptoms of heart failure. The following cut-off values for each echocardiographic and electrocardiographic parameter predisposing to PAS < 95% during VDD/R pacing ('undersensing') were identified: RVEDd > 26 mm, RVESd > 24 mm, LVEDd > 59 mm, LVESd > 37.3 mm, APD LA > 44 mm, SID RA > 52 mm, LMD RA > 48 mm, RAvol> 54 ml, RAarea > 19 cm2, SID LA > 57 mm, LMD LA > 46 mm, EF < 52%, P wave width > 100 ms. Significant predictors of PAS < 95% in the univariate analysis were RVEDd, RVESd, LVEDd, LMD RA, SID RA, RAvol, RAarea, EF, and in the multivariate analysis RVEDd, RVESd, LMD RA, RAarea, EF. CONCLUSIONS: Selected parameters obtained from ECG (P wave width) and echo examinations are correlated with effective AV synchronisation. Enlargement of the right and left heart chambers (atrial, ventricular), reduction of the ejection fraction and congestive heart failure are associated with impaired AV synchronisation in VDD/R pacemakers. In multivariate analysis, only the higher dimensions of the right ventricle and atrium and the lower ejection fraction of the left ventricle were significantly associated with the PAS < 95%.

[Cardiac resynchronization therapy in refractory heart failure]. / Terapia resynchronizujaca w niewydolnosci serca.

Congestive heart failure remains associated with substantial morbidity and mortality. A common finding in advanced heart failure is abnormal electrical activation of the ventricles or electrical ventricular dyssynchrony. In the early 90s, standard dual-chamber pacing with short AV delay was proposed as a supplementary treatment of drug-resistant heart failure. Initial results were encouraging but were never confirmed. These studies however made it possible to select a population of potentially responsive patients, especially those with a prolonged PR interval reflecting major atrioventricular asynchrony in the left heart. That relative failure of standard dual-chamber pacing could be linked to the fact that by capturing the ventricle from the right apex, it increases, or at least it cannot correct the marked asynchrony of activation, contraction and relaxation, which characterizes a number of patients with chronic left ventricular dysfunction. Such is the case in particular in patients with important QRS enlargement linked to major intraventricular conduction delay. Biventricular pacing, which simultaneously activates both ventricles, may contribute to correcting the asynchrony and thus improve cardiac performance.

[Ineffective atrial pacing and cardiac arrest in a 80-year old woman with hyperkalemia]. / Nieskuteczna stymulacja przedsionkowa i zatrzymanie krazenia u osiemdziesiecioletniej chorej z hiperkaliemia.

A case of 80-year-old woman with marked hyperkalemia in the course of chronic treatment with angiotensin converting enzyme (ACE) inhibitors and spironolactone is presented. AAI pacemaker was implanted three months ago. The ECG revealed a nodal rhythm, ineffective AAI pacing and other typical features of hyperkalemia. After normalisation of potassium level the ECG changes disappeared. Potential mechanism of the nodal rhythm during ineffective atrial pacing is discussed.

[Patients history following artificial aortic valve and pacemaker implantation]. / Losy chorych po implantacji sztucznej zastawki aortalnej i rozrusznika serca.

UNLABELLED: The follow-up of 22 patients (out of 31 patients after artificial aortic valve and pacemaker implantation between 1982 and 2001) have been evaluated. There were 15 men aged 30-76 (x=55) and 7 women aged 43-69 (x=59). Aortic valve replacement (AVR) was subsequently followed by pacemaker implantation (PI) after approximately 16 days. Indication for permanent stimulation were: atrio-ventricular complete block in 18 patients and atrial fibrillation with slow ventricular response in the remaining 4. There were implanted 15 devices of VVI type and 7 of VDD type. The duration of follow up was 9-196 (x=56) months. All these patients remained in good general state (II degree--19 patients or II/III degree--3 patients acc. to NYHA classification). In 21 out of 22 patients, atrioventricular conduction disturbances and bradyarrhythmia remained for the entire follow-up duration with permanent stimulation (VVI or VAT). In one patient the postoperative complete atrio-ventricular block disappeared during follow up, 24 months after AVR. CONCLUSIONS: 1. The main indication for PI after AVR was complete atrio-ventricular block, persisting 2-3 weeks after surgery, without accompanying atrial fibrillation. 2. In long term follow up after AVR and PI (VVI or VDD) the dominance of 100% capture ventricular pacing have been recorded in almost all cases, which holds the decision of early postoperative PI.

[Long-term results of radiofrequency (RF) catheter ablation of cardiac arrhythmias]. / Odlegla skutecznosc zabiegów przezskórnej ablacji RF w leczeniu zaburzen rytmu serca--doswiadczenia wlasne.

BACKGROUND: Although the short-term results after radiofrequency (RF) catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT), accessorry pathway (AP), atrioventricular junction (AVJ) and common atrial flutter (Aflu) have been widely reported, there is insufficient data on long-term outcome. AIM: To evaluate the long-term efficacy of RF ablation of cardiac arrhythmias in a single center. METHODS: The study population consisted of 349 consecutive patients (mean age 49.5 years) who underwent RF ablation of AP (136 patients), AVNRT (105 patients), AVJ (86 patients) or Aflu (15 patients). In 4 patients two AP and in 3 patients AP and AVNRT were ablated during the same session. The patients were subsequently followed-up for an average of 44.3 months (12-76 months). RESULTS: Ablation was successful in 341 patients (97.7%). Major complications occurred in 8 patients (2.3%) and included av block (6 patients), ventricular fibrillation (1 patient) and cardiac tamponade (1 patient). Tachycardia recurrences were observed in 21 patients (6.2%) after successful ablation. All the recurrences occurred within 10 months (mean 2.3 months) after ablation. The recurrence rate was 5.8% (6 patients) in the AVNRT group, 9.2% (12 patients) in the AP group, 1.2% in the AVJ group (1 patient) and 13% (2 patients) in the Aflu group. The differences between groups were insignifficant. CONCLUSIONS: (1) The immediate success rate of RF ablation of AVNRT, AP, AVJ or Aflu was high and there was a low incidence of complications. (2) The recurrence rate during long-term observation is low. (3). All the recurrences occurred within 10 months after successful ablation.