Brain embolism, left atrial thrombi and cardiosurgery.

Patients with embolization into the brain and mobile thrombus in the left atrium (LA) are in the danger of recurrent embolization. A patient with the history of recent cerebral vascular accident (CVA) would be at higher risk of cerebral complications due to cardiopulmonary bypass and this risk may be as high as that of re-embolization. We present a case of a 41-year old man with an acute ischemic focus (3 x 3 cm) in the temporoparietal lobe verified by computer tomography (CT). Transthoracic echocardiography showed severe aortic insufficiency, low ejection fraction of dilatated left ventricle (LV). Transesophageal echocardiography showed a mobile thrombus (2.2 x 1.1 cm) in LA. The cardiovascular surgeon consultant did not recommend urgent operation. Instead, the patient was treated by low molecular heparin. CT of the brain after 10 days of treatment was normal. Patient underwent a successful aortic valve replacement. At the time of surgery there was no thrombus in the LA. Subsequently, the patient recovered normally with no neurologic sequelae. This case illustrates the difficulty arising from the consideration of the relative risks of acute surgery vs conservative management in patient with recent CVA and a large mobile thrombus in LA.

Early benefit of implantable cardioverter defibrillator therapy in patients waiting for cardiac transplantation.

The ICD can effectively recognize and treat ventricular arrhythmias that can lead to sudden death. Sudden death is a major problem in patients awaiting heart transplantation. We reviewed our experience with the ICD in patients with malignant ventricular arrhythmias waiting for cardiac transplantation. Nineteen patients were included. Seventeen were men, mean age was 54 +/- 11 years (range 17-66) and the left ventricular ejection fraction was 22% +/- 10% (range 9%-46%). After a mean follow-up of 6 +/- 5 months (range 1-20 months), 17 patients reached heart transplantation. One patient died and the other is waiting for a transplant. Before transplantation 71% of patients received an appropriate discharge. The mean time to the first appropriate discharge was 2 +/- 2 months (range < 1-6 months), which was significantly shorter than the mean time to first discharge in the other patients (n = 182) receiving a defibrillator in our center (11 +/- 10 months; range 1-58 months) (P < 0.0004). In conclusion, cardiac transplantation candidates with life-threatening ventricular arrhythmias can effectively be protected against sudden arrhythmic death by ICD. These patients have a high incidence of appropriate shocks occurring very early after implantation.

[Intracoronary pressure and its significance in the clinical evaluation of patients with ischemic heart disease]. / Intrakoronárne tlaky a ich význam pre klinické hodnotenie pacientov s ischemickou chorobou srdca.

Assessment of coronary artery disease is a highly relevant problem in current cardiology. Although, coronary angiography still remains the ultimate diagnostic test to prove the presence of coronary narrowings, it is increasingly becoming obvious that a refine understanding of the atherosclerosclerotic lesions and its consequences on perfusion of the underlying myocardium requires much more than just the silhouette of the arterial lumen provided by contrast angiography. This knowledge together with the current therapeutic invasive approaches has led to the introduction of new invasive methods to demonstrate the haemodynamic significance of a given lesion. In this brief review we describe the importance, feasibility and usefulness of transstenotic pressure gradient measurements. Furthermore, we provide the description of myocardial fractional flow reserve as a new functional index for the assessment of the coronary stenosis severity and its effects on maximal myocardial perfusion. This index, by interpreting the transstenotic pressure gradient in combination with mean aortic and central venous pressure offers a complex and easy assessment of coronary haemodynamics. On the basis of our recent experience we discuss the applications of the presented concept in daily clinical practice. (Tab. 3, Fig. 4, Ref. 25.).

Prognostic significance of transient complete atrioventricular block during radiofrequency ablation of atrioventricular node reentrant tachycardia.

One hundred eighty-six consecutive patients underwent radiofrequency ablation and were divided into 2 groups: group 1 included 19 patients (13 women, mean age 50 +/- 15 years) with transient atrioventricular (AV) block during the procedure. The duration of AV block ranged from 4 seconds to 30 minutes (mean 2.8 +/- 7.0 minutes); and group 2 included 167 patients (142 women, mean age 40 +/- 17 years) without transient AV block. Follow-up was 8.6 +/- 8.3 months in group 1 and 10.1 +/- 9.4 months in group 2. No significant differences were observed between the 2 groups concerning the ablation approach (fast or slow pathway), the number of radiofrequency applications, and recurrences of tachycardia. Four patients from group 1 who underwent fast pathway ablation developed late complete AV block, whereas no patient in group 2 had such a complication (p = 0.0001). Late complete AV block occurred 20 hours, 6 days, 1 month, and 25 days after ablation, respectively, and was not related to the duration of transient AV block. Another patient from group 1 developed an asymptomatic 2:1 AV block during exercise, 3 months after slow pathway ablation. Transient AV block, a common finding occurring as often during fast as during slow pathway ablation, did not preclude recurrences of tachycardia but was associated with late complete AV block.

[Radiofrequency catheter ablation of atrial tachycardia]. / Rádiofrekvencná katétrová predsiennovej tachykardie.

BACKGROUND AND OBJECTIVE: Radiofrequency catheter ablation has proved to be highly effective for the treatment of supraventricular tachycardia originating in the AV node or related to atrioventricular accessory pathways. However, experience with ablation of atrial tachycardia is more limited. The purpose of our study was to analyse the success and safety of radiofrequency ablation of atrial tachycardias. STUDY POPULATION: Ten symptomatic patients with drug refractory atrial tachycardia. Symptoms included palpitations, dizziness, chest pains, shortness of breath, syncope. Five patients had reduced left ventricular ejection fraction (tachycardiomyopathy). METHODS: Radiofrequency device - Medtronic ATAKRR with temperature monitoring. Temperature ranges from 50 degrees C to 70 degrees C were considered optimal to ablation. Ablation catheter - 7 F CardiorhythmR with a 4 mm2 deflectable tip. Heparin was given intravenously during the procedure (5000 IU bolus + 1000 IU/h). Acetylsalicylic acid 160 mg/day for 1 month after the procedure. Antiarrhythmic drugs were discontinued after the procedure. The sites for ablation were defined during tachycardia by the earliest endocardial atrial activation as compared to the onset of the surface P wave. Criteria of success: Abolition of the tachycardia followed by the inability to reinduce the tachycardia. FOLLOW-UP: Clinical, ECG and 2D ECHO evaluation in the outpatient's clinic. No complications occurred during the procedure. No reccurrences of the tachycardia were observed during the follow-up. All 5 patients with reduced ejection fraction before ablation had normal left ventricular function during follow-up. CONCLUSION: Radiofrequency catheter ablation is a safe and effective treatment for drug refractory atrial tachycardia.

Radiofrequency ablation of atrioventricular node reentrant tachycardia: experience in 302 patients.

Radiofrequency catheter ablation was performed in 302 consecutive patients with drug refractory atrioventricular (AV) node reentrant tachycardia. Fast pathway ablation was attempted in 167 patients and was successful in 161 patients (96.4%). At a mean follow-up of 24 +/- 12 months, there were 21 tachycardia recurrences (12.5%). A second fast pathway ablation was attempted in 17 patients and was successful in all but 1 patient. Permanent complete AV block occurred in 12 patients (7.2%). Among the latter, late AV block was noted in 5 patients. Final success without pacemaker implantation was accomplished in 151 patients (90.4%). Slow pathway was attempted in 135 patients and was successful in 130 patients (96.3%). Three patients in whom slow pathway ablation failed underwent successful fast pathway ablation during the same session. At a mean follow-up of 14 +/- 11 months, there were 16 tachycardia recurrences (11.8%). A second slow pathway ablation was attempted in 16 patients and was successful in all but 1 patient. Permanent complete AV block occurred in 3 patients (2.2%). An additional patient developed 2 : 1 AV block during exercise, 3 months after ablation. Final success without pacemaker implantation was achieved in 129 patients (95.5%). Fast and slow pathway ablation had similar success and recurrence rates, procedure and fluoroscopy times, and number of radiofrequency pulses. However, the incidence of permanent complete AV block was higher following fast pathway ablation (p = 0.049). Although equally effective, slow pathway ablation is safer than fast pathway ablation, therefore, should be the first choice approach for treatment of AV node reentrant tachycardia.

[Vectorcardiographic features of right ventricular dilatation]. / Vektorokardiografický obraz dilatácie pravej komory.

Axial McFee-Parungao lead system vectorcardiograms were obtained in 55 patients with type atrial septal defect, aged 3-24 years, prior to and in average 3 years after surgical repair of the defect. Changes of the QRS loop observed after intervention led to the conclusion that the vectorcardiographic signs of right ventricular dilatation consist of a rightward shift of the posteriorly orientated horizontal plane vectors at 50-70 ms of QRS, decrease of the magnitude of vectors around the 40th ms, no changes in the magnitude and orientation of the initial (10-30 ms) QRS vectors as well abnormal departures of the spatial VCG loop from its preferential plane even in the absence of other signs of right ventricular conduction impairment. The above abnormalities vanished after normalization of hemodynamics.