Dóra Paprika

Human autonomic responses to blood donation

In order to characterize autonomic responses to acute volume loss, supine ECG, blood pressure (BP) and uncalibrated breathing signal (UBS) recordings were taken before and after blood donation in 48 healthy volunteers. Time and frequency domain parameters of RR interval (RRI), BP and UBS variability were determined. Baroreflex gain was calculated by the technique of the spontaneous sequences and cross-spectral analysis. The systolic (SAP), diastolic (DAP) and mean BP (MAP) increased after the blood withdrawal. The central frequency of breathing and mean heart rate did not change. RRI variability increased in low frequency band (LF), tended to decrease in high frequency band (HF). Systolic BP variability increased in both frequency bands, but was statistically significant only in the high frequency band. Diastolic BP power increased in both frequencies. From the different baroreflex gain estimates, up sequence BRS and HF alpha index decreased significantly. The phase angle between RRI and systolic blood pressure powers in LF band did not change (-58 +/- 24 degrees and -54 +/- 26 degrees ). In the high frequency range, the phase became more negative (-1 +/- 29 degrees and -17 +/- 32 degrees, p = 0.001). The withdrawal of 350-400 ml blood in 5 min resulted in sympathetic activation, which was reflected in increased systolic, diastolic and mean BP. The increased BP oscillation was a sensitive marker of the minor volume depletion. This was coupled by increased RRI oscillation via baroreflex mechanisms in the LF band. Changes in the RRI and BP oscillations in the HF band showed no similar coupling. That points to the fact that RRI oscillations in this band should not be explained entirely by baroreflex mechanisms. Vagal withdrawal was reflected in decreased root mean square of successive differences (RMSSD), decreased HF RRI power and decreased up sequence BRS.

Measures of cardiovascular autonomic regulation derived from spontaneous methods and the Valsalva maneuver.

The response of heart rate to a given change of systolic blood pressure is a fundamental characteristic of the cardiovascular system. The assessment of baroreflex gain (BRS) as an index of baroreflex function is based on the quantification of RR interval changes related to blood pressure changes. The spontaneous sequence and cross spectral methods describe baroreflex gain derived from spontaneous fluctuations of these parameters, yielding the up sequence and down sequence BRS and the alfa index. Phase IV of the Valsalva maneuver is also used to calculate cardiac vagal baroreflex gain. In this study, we compared the two spontaneous methods and the Valsalva maneuver in assessing baroreflex gain in 56 healthy volunteers. The BRS values calculated from different methods were as follows: up sequence BRS 12 +/- 8.6 ms/mm Hg, down sequence BRS 10 +/- 6.1 ms/mm Hg, low frequency alfa index 12.1 +/- 8.2 ms/mm Hg, Valsalva BRS 9.7 +/- 7.2 ms/mm Hg. We found close relationship between baroreflex gain derived from up and down sequences (R = 0.91, p < 0.001), down sequence BRS and low frequency alfa index (R = 0.81, p < 0.001); significant correlation between up sequence BRS and low frequency alfa index (R = 0.65, p < 0.001), the Valsalva-derived BRS and down sequence BRS (R = 0.37, p = 0.043), but no correlation between the Valsalva BRS and up sequence BRS, the Valsalva BRS and low frequency alfa index. BRS values calculated by different methods decreased with increasing age. There was no influence of age on mean arterial blood pressure elevation in late phase II of the Valsalva maneuver, nor any indication that the Valsalva BRS was related to the MAP changes. We concluded that all of these methods are useful in calculating baroreflex gain, but owing to the differences in underlying physiological mechanisms, they are not necessarily in correlation with each other.

Mid-term echocardiographic follow up of left ventricular function with permanent right ventricular pacing in pediatric patients with and without structural heart disease

BackgroundChronic right ventricular apical pacing may have detrimental effect on left ventricular function and may promote to heart failure in adult patients with left ventricular dysfunction.MethodsA group of 99 pediatric patients with previously implanted pacemaker was studied retrospectively. Forty-three patients (21 males) had isolated congenital complete or advanced atrioventricular block. The remaining 56 patients (34 males) had pacing indication in the presence of structural heart disease. Thirty-two of them (21 males) had isolated structural heart disease and the remaining 24 (13 males) had complex congenital heart disease. Patients were followed up for an average of 53 ± 41.4 months with 12-lead electrocardiogram and transthoracic echocardiography. Left ventricular shortening fraction was used as a marker of ventricular function. QRS duration was assessed using leads V5 or II on standard 12-lead electrocardiogram.ResultsLeft ventricular shortening fraction did not change significantly after pacemaker implantation compared to preimplant values overall and in subgroups. In patients with complex congenital heart malformations shortening fraction decreased significantly during the follow up period. (0.45 ± 0.07 vs 0.35 ± 0.06, p = 0.015). The correlation between the change in left ventricular shortening fraction and the mean increase of paced QRS duration was not significant. Six patients developed dilated cardiomyopathy, which was diagnosed 2 months to 9 years after pacemaker implantation.ConclusionChronic right ventricular pacing in pediatric patients with or without structural heart disease does not necessarily result in decline of left ventricular function. In patients with complex congenital heart malformations left ventricular shortening fraction shows significant decrease.

Ice mapping during tachycardia in close proximity to the AV node is safe and offers advantages for transcatheter ablation procedures.

Background — Ablation during ongoing orthodromic reentry tachycardia (AVRT) and atrioventricular nodal reentry tachycardia (AVNRT) is not recommended using radiofrequency energy when the arrhythmia substrate is located in close proximity to the atrioventricular (AV) node due to a significant risk for inadvertent AV block. The aim of the study is to test the feasibility of ice mapping during tachycardias involving arrhythmia substrate located in close proximity to the AV node. Methods — This was a single-centre, prospective, randomized study. A total of 65 patients was screened and 30 patients with supraventricular arrhythmias were assigned either to a cryo or RF energy group after diagnosis of AVNRT (17 pts) or AVRT (13 pts) with an anteroseptal accessory pathway. RF ablation was performed using standard ablation techniques. In the cryo group, ice mapping was performed during tachycardia with cooling of the catheter tip temperature to a maximum of —40°C. Ablation was performed only if ice mapping terminated the tachycardia without prolongation of the AV conduction. Results — The overall acute success rate was 84%, and was not different in the cryo and RF groups (85% vs. 82.4%, P = 0.43). Both fluoroscopy and the procedure times were comparable.There was a marked reduction in the mean number of applications in the cryo group [2 (1-6) vs. 7 (1-41), P = 0.002]. In one patient ablation was not attempted in the cryo group because of AV prolongation, and in two patients temporary second-degree AV block was observed in the RF group. After 12 months follow-up the long-term success rate was similar between the two groups. Conclusions — (1) Ice mapping is a feasible method to determine the exact location of accessory pathways and of the slow pathway during tachycardia. (2) Ice mapping performed during tachycardia causes less ablation lesions without increasing the procedure and fluoroscopy times.

Bi-atrial and right atrial activation times help to differentiate focal from macroreentrant right atrial tachycardias

Objective — The objective was to study atrial activation intervals and their relation to the tachycardia cycle length (TCL) as electrophysiologic parameters differentiating focal (FAT) from macroreentrant atrial tachycardias (MRAT) originating in the right atrium. Methods — In 21 patients (8 men) with 30 successfully ablated right atrial tachycardias (15 focal) the endocardial activity during tachycardia was registered using multipolar catheters in the right atrium and the coronary sinus. Using this catheter configuration we measured the tachycardia cycle length (TCL), biatrial activation (BAA), right atrial activation (RAA), left atrial activation (LAA), as well as the proportion of those intervals to TCL. In 14 patients, the measurements were repeated in sinus rhythm as well. The diagnostic accuracy of the ratio of BAA to TCL was assessed. Results — TCL was longer, but all other intervals and ratios were significantly shorter in FAT compar dto MRAT (P < 0.05 for all parameters, except for LAA – P= NS). During sinus rhythm, patients with MRAT had prolonged RAA (P = 0.003), but not BAA and LAA (P= NS), compred to patients with FAT. A discriminating value of 40% for the ratio of BAA to TCL, compared to 50% and 30%, was found to have the best sensitivity, specificity, positive and negative predictive values for MRAT, as well as for FAT. Conclusions — BAA, RAA, LAA and their relation to the TCL are significantly shorter in FATs compared to MRATs arising from the right atrium. The ratio of BAA to TCL obtained using a simple 2-catheter configuration, allows a rapid and reliable differentiation between FAT and MRAT.

Veleszületett szívbetegséghez társuló ritmuszavarok katéterablatiós kezelése

disturbances are common long after surgical repair of congenital heart disease. These arrhythmias caused by the progres sion of the disease itself, however, a significant proportion is a result of the presence of surgical scar. Although interventional electrophysiology procedures are complex and encounter difficulties, pharmacological therapy is often very disappo inting.Aimandmethods: In the present study we aimed to describe our experience obtained between 2004 and 2006 in patients undergoing transcatheter ablation long after surgery for congenital heart disease.Results: During this period 26 patients underwent catheter ablation. The procedure was successful in 24 out of the 26 patients (92%). Three patients re quired redo ablations due to arrhythmia recurrences (11%). There were no major complications related to the interven tion. In four patients minor complications occured (small hematomas).Conclusions: Our descriptive data indicate that transcatheter ablation for arrhythmias after surgery for congenital heart disease is a effective safe and more importantly cu rative procedure. It is associated with reasonable success rate, low complication rate, but slightly higher recurrence rate as compared to the classical electrophysiological interventions.UNLABELLED Rhythm disturbances are common long after surgical repair of congenital heart disease. These arrhythmias caused by the progression of the disease itself, however, a significant proportion is a result of the presence of surgical scar. Although interventional electrophysiology procedures are complex and encounter difficulties, pharmacological therapy is often very disappointing. AIM AND METHODS In the present study we aimed to describe our experience obtained between 2004 and 2006 in patients undergoing transcatheter ablation long after surgery for congenital heart disease. RESULTS During this period 26 patients underwent catheter ablation. The procedure was successful in 24 out of the 26 patients (92%). Three patients required redo ablations due to arrhythmia recurrences (11%). There were no major complications related to the intervention. In four patients minor complications occurred (small hematomas). CONCLUSIONS Our descriptive data indicate that transcatheter ablation for arrhythmias after surgery for congenital heart disease is a effective safe and more importantly curative procedure. It is associated with reasonable success rate, low complication rate, but slightly higher recurrence rate as compared to the classical electrophysiological interventions.

Unusual wenckebach phenomenon due to an atrial tachycardia arising from the apex of koch's triangle in the presence of dual AV nodal physiology

A case of a patient with narrow QRS tachycardia and without structural heart disease is presented. The electrophysiologic study revealed an atrial tachycardia in the presence of dual atrioventricular (AV) nodal physiology and AV block at suprahisian level, the latter two leading to an unusual Wenckebach periodicity. The entire septal area was mapped as was the coronary sinus (CS) os and the earliest atrial activation was found at the apex of Koch’s triangle in close vicinity to the His bundle (HB). Cryomapping at that point reproducibly terminated the tachycardia without impairing AV conduction. Cryoablation rendered the tachycardia non-inducible. Discontinuous AV conduction persisted but AV nodal reentrant tachycardia (AVNRT) was not inducible. Six months later the patient is arrhythmia-free.

The effects of acute blood loss on blood pressure recovery from the Valsalva maneuver

Human baroreflex regulation plays an important role in stabilising blood pressure. Though we have several indices to quantify cardiovagal responses, sympathetic baroreflex gain remains difficult to assess. We investigated how the recently validated pressure recovery time (PRT) and sympathetic baroreflex gain (SBRS) derived from the Valsalva maneuver was influenced by acute blood loss. 26 healthy blood donors were included in the study (age 35 ± 15 years; 20 men). SBRS was derived from the blood pressure drop (SAP delta) and pressure recovery time during the Valsalva maneuver. Besides we calculated cardiovagal baroreflex parameters, the Valsalva ratio (VR) and a simplified baroreflex gain (VBRS). We compared these parameters before and after the withdrawal of 350-400 ml blood. The baseline systolic blood pressure was the same before and after blood donation (123 ± 17 vs 126 ± 23 mm Hg, NS). The minimum systolic pressure (SAP min) during phase III was significantly lower, and the SAP delta significantly greater after blood withdrawal (SAP min 83 ± 24 mm Hg vs 69 ± 27 mm Hg, p<0.001; SAP delta 41 ± 15 mm Hg vs 57 ± 16 mm Hg, p<0.001). PRT increased significantly (from 2.0 to 3.6s, p<0.006). SBRS did not change between the study conditions (24 ± 12 mm Hg/s vs 22 ± 10 mm Hg/s, NS), nor did the VR and the VBRS: In conclusion, after the acute loss of approximately 350-400 ml blood there was a greater blood pressure drop in phase II and III and a slower blood pressure recovery in phase IV of the Valsalva maneuver that resulted in an unchanged SBRS.

Treatment of arrhythmias associated with surgery for congenital heart disease using transcatheter ablation

disturbances are common long after surgical repair of congenital heart disease. These arrhythmias caused by the progres sion of the disease itself, however, a significant proportion is a result of the presence of surgical scar. Although interventional electrophysiology procedures are complex and encounter difficulties, pharmacological therapy is often very disappo inting.Aimandmethods: In the present study we aimed to describe our experience obtained between 2004 and 2006 in patients undergoing transcatheter ablation long after surgery for congenital heart disease.Results: During this period 26 patients underwent catheter ablation. The procedure was successful in 24 out of the 26 patients (92%). Three patients re quired redo ablations due to arrhythmia recurrences (11%). There were no major complications related to the interven tion. In four patients minor complications occured (small hematomas).Conclusions: Our descriptive data indicate that transcatheter ablation for arrhythmias after surgery for congenital heart disease is a effective safe and more importantly cu rative procedure. It is associated with reasonable success rate, low complication rate, but slightly higher recurrence rate as compared to the classical electrophysiological interventions.UNLABELLED Rhythm disturbances are common long after surgical repair of congenital heart disease. These arrhythmias caused by the progression of the disease itself, however, a significant proportion is a result of the presence of surgical scar. Although interventional electrophysiology procedures are complex and encounter difficulties, pharmacological therapy is often very disappointing. AIM AND METHODS In the present study we aimed to describe our experience obtained between 2004 and 2006 in patients undergoing transcatheter ablation long after surgery for congenital heart disease. RESULTS During this period 26 patients underwent catheter ablation. The procedure was successful in 24 out of the 26 patients (92%). Three patients required redo ablations due to arrhythmia recurrences (11%). There were no major complications related to the intervention. In four patients minor complications occurred (small hematomas). CONCLUSIONS Our descriptive data indicate that transcatheter ablation for arrhythmias after surgery for congenital heart disease is a effective safe and more importantly curative procedure. It is associated with reasonable success rate, low complication rate, but slightly higher recurrence rate as compared to the classical electrophysiological interventions.

Veleszületett szívbetegséghez társuló ritmuszavarok katéterablatiós kezelése@@@Treatment of arrhythmias associated with surgery for congenital heart disease using transcatheter ablation

disturbances are common long after surgical repair of congenital heart disease. These arrhythmias caused by the progres sion of the disease itself, however, a significant proportion is a result of the presence of surgical scar. Although interventional electrophysiology procedures are complex and encounter difficulties, pharmacological therapy is often very disappo inting.Aimandmethods: In the present study we aimed to describe our experience obtained between 2004 and 2006 in patients undergoing transcatheter ablation long after surgery for congenital heart disease.Results: During this period 26 patients underwent catheter ablation. The procedure was successful in 24 out of the 26 patients (92%). Three patients re quired redo ablations due to arrhythmia recurrences (11%). There were no major complications related to the interven tion. In four patients minor complications occured (small hematomas).Conclusions: Our descriptive data indicate that transcatheter ablation for arrhythmias after surgery for congenital heart disease is a effective safe and more importantly cu rative procedure. It is associated with reasonable success rate, low complication rate, but slightly higher recurrence rate as compared to the classical electrophysiological interventions.UNLABELLED Rhythm disturbances are common long after surgical repair of congenital heart disease. These arrhythmias caused by the progression of the disease itself, however, a significant proportion is a result of the presence of surgical scar. Although interventional electrophysiology procedures are complex and encounter difficulties, pharmacological therapy is often very disappointing. AIM AND METHODS In the present study we aimed to describe our experience obtained between 2004 and 2006 in patients undergoing transcatheter ablation long after surgery for congenital heart disease. RESULTS During this period 26 patients underwent catheter ablation. The procedure was successful in 24 out of the 26 patients (92%). Three patients required redo ablations due to arrhythmia recurrences (11%). There were no major complications related to the intervention. In four patients minor complications occurred (small hematomas). CONCLUSIONS Our descriptive data indicate that transcatheter ablation for arrhythmias after surgery for congenital heart disease is a effective safe and more importantly curative procedure. It is associated with reasonable success rate, low complication rate, but slightly higher recurrence rate as compared to the classical electrophysiological interventions.