Functional substrate mapping of atrium in patients with atrial scar: A novel method to predict critical isthmus of atrial tachycardia.

Atrial tachycardia (AT) is a common rhythm disorder, especially in patients with atrial structural abnormalities. Although voltage mapping can provide a general picture of structural alterations which are mainly secondary to prior ablations, surgery or pressure/volume overload, data is scarce regarding the functional characteristics of low voltage regions in the atrium to predict critical isthmus of ATs. Recently, functional substrate mapping (FSM) emerged as a potential tool to evaluate the functionality of structurally altered regions in the atrium to predict critical sites of reentry. Current evidence suggested a clear association between deceleration zones of isochronal late activation mapping (ILAM) during sinus/paced rhythm and critical isthmus of reentry in patients with left AT. Therefore, these areas seem to be potential ablation targets even not detected during AT. Furthermore, abnormal conduction detected by ILAM may also have a role to identify the potential substrate and predict atrial fibrillation outcome after pulmonary vein isolation. Despite these promising findings, the utility of such an approach needs to be evaluated in large-scale comparative studies. In this review, we aimed to share our experience and review the current literature regarding the use of FSM during sinus/paced rhythm in the prediction of re-entrant ATs and discuss future implications and potential use in patients with atrial low-voltage areas.

Evaluation of cardiac arrhythmia in pediatric patients with Left Ventricular Assist Device (L-VAD).

OBJECTIVE: Pediatric heart failure is an important cause of morbidity and mortality in childhood. Left ventricular assist devices (L-VAD) are used for bridging to transplantation in patients with indications for heart transplantation. PATIENTS AND METHODS: The children included in the study were patients who underwent implantation of an L-VAD due to advanced heart failure at Ege University Faculty of Medicine Hospital between January 2009 and January 2023. RESULTS: Of the 33 patients who underwent L-VAD implantation, 16 (48.5%) were female and 17 (51.5%) were male. The median age at surgery was 13 years (IQR, 9.5-15). The median weight was 44 kg (IQR, 25.65-52), the median height was 158 cm (IQR, 134.5-168.5), and the median body surface area was 1.37 m2 (IQR, 0.95-1.51). All patients who underwent L-VAD implantation had an echocardiographic diagnosis of dilated cardiomyopathy. The patients underwent a median of 16 (IQR, 9-21) ECGs, and the median number of 24-hour Holter ECGs obtained was 3 (IQR, 2-5). Arrhythmias that occurred after L-VAD implantation were classified as atrial and ventricular. Ventricular arrhythmia included ventricular tachycardia (VT) lasting for more than 30 seconds (sustained VT), VT lasting for less than 30 seconds (nonsustained VT), and ventricular fibrillation. Atrial arrhythmias included atrial flutter, atrial fibrillation, supraventricular tachycardia, and atrial ectopic tachycardia. During the follow-up, atrial or ventricular arrhythmias were observed in 11 (33%) patients. The most common rhythm disturbances before L-VAD implantation were ventricular arrhythmias, while after the surgery, atrial arrhythmias were found to be the most frequent. A total of 5 patients underwent cardioversion (n=2) or defibrillation (n=3) due to arrhythmia. CONCLUSIONS: In patients undergoing L-VAD implantation, rhythm disorders that could normally lead to hemodynamic instability are frequently encountered. In these rhythm disorders, medical therapy should be attempted before resorting to cardioversion or defibrillation, and subsequently, more aggressive treatment methods should be considered.

Catheter ablation of atrial arrhythmias in cardiac amyloidosis: Impact on heart failure and mortality.

BACKGROUND: Atrial arrhythmias (AA) commonly affect patients with cardiac amyloidosis (CA) and are a contributing risk factor for the development of heart failure (HF). This study sought to investigate the long-term efficacy and impact of catheter ablation on HF progression in patients with CA and AA. METHODS: Thirty-one patients with CA and AA undergoing catheter ablation were retrospectively included (transthyretin-ATTR CA 61% and light chain-AL CA 39%). AA subtypes included atrial fibrillation (AFib) in 22 (paroxysmal in 10 and persistent in 12), atrial flutter (AFl) in 17 and atrial tachycardia (AT) in 11 patients. Long-term AA recurrence rates were evaluated along with the impact of sinus rhythm (SR) maintenance on HF and mortality. RESULTS: AA recurrence was observed in 14 patients (45%) at a median of 3.5 months (AFib n = 8, AT n = 6, AFl = 0). Post-cardioversion, medical therapy or catheter ablation, 10 patients (32%) remained in permanent AA. Over a median follow-up of 19 months, all-cause mortality was 39% (n = 12): 3 with end-stage HF, 5 due to late complications of CA, 1 sudden cardiac death, 1 stroke, 1 COVID 19 (and one unknown). With maintenance of SR following catheter ablation, significant reductions in serum creatinine and natriuretic peptide levels were observed with improvements in NYHA class. Two patients required hospitalization for HF in the SR maintenance cohort compared to 5 patients in the AA recurrence cohort (p = 0.1). All 3 patients with deaths secondary to HF had AA recurrence compared to 11 out of the 28 patients whom were long-term survivors or deaths not related to HF (p = 0.04). All-cause mortality was not associated with AA recurrence. CONCLUSION: This study demonstrates moderate long-term efficacy of SR maintenance with catheter ablation for AA in patients with CA. Improvements in clinical and biological status with positive trends in HF mortality are observed if SR can be maintained.

Torsades de pointes and myocardial infarction following reversal of supraventricular tachycardia with adenosine: a case report.

Adenosine is an antiarrhythmic drug that slows conduction through the atrioventricular node and acts as a coronary blood vessel dilator. This case report highlights two unusual life-threatening events following the use of adenosine to revert supraventricular tachycardia in a structurally normal heart: non-sustained polymorphic ventricular tachycardia and myocardial infarction. A 46-year-old woman presented to the emergency department with a two-hour history of palpitations and was diagnosed with supraventricular tachycardia. Vagal maneuvers were ineffective, and after intravenous adenosine administration, the patient presented with chest pain and hypotension. The rhythm degenerated into non-sustained polymorphic ventricular tachycardia and spontaneously reverted to sinus rhythm with ST elevation in lead aVR and ST depression in the inferior and anterolateral leads. The patient spontaneously recovered within a few minutes. Despite successful arrhythmia reversal, the patient was admitted to the intensive care unit because of an infarction without obstructive atherosclerosis. This report aims to alert emergency physicians about the potential complications associated with supraventricular tachycardia and its reversal with adenosine.

Non-paroxysmal junctional tachycardia complicating disseminated intravascular coagulation during massive surgical hemorrhage: A case report.

RATIONALE: Non-paroxysmal junctional tachycardia (NPJT) is a self-limiting supraventricular tachycardia associated with primary heart disease, cardiac surgery, digitalis toxicity, and metabolic or electrolyte imbalances. However, NPJT caused enhanced normal automaticity even in the absence of structural heart disease can be fatal if not managed properly. PATIENT CONCERNS: A 74-year-old hypertensive female patient was scheduled for transureteroureterostomy and right ureteroneocystostomy under general anesthesia. DIAGNOSIS: The patient developed NPJT without visible P wave and severe hypotension due to adrenergic stimulation in response to massive hemorrhage during surgery. INTERVENTIONS: NPJT with hypotension was initially converted to sinus rhythm with normotension with administration of adenosine and esmolol. However uncontrolled surgical hemorrhage and administration of large dose of vasopressors eventually perpetuated NPJT refractory to antiarrhythmic drugs. OUTCOMES: Despite intravenous fluid resuscitation and massive transfusion, the patient was deteriorated hemodynamically due to uncontrolled bleeding and persistent NPJT, which resulted in hypovolemic shock and fatal disseminated intravascular coagulation (DIC). LESSONS: NPJT can occur by enhanced automaticity due to increased catecholamine during severe surgical hemorrhage. Although NPJT is generally self-limiting, it can be refractory to antiarrhythmic agents and accelerate hypotension if the surgical bleeding is uncontrolled. Therefore, aggressive management of the primary pathologic condition is crucial for the management of NPJT and hemodynamic collapse even in the absence of structural heart disease.

FLRT3 and TGF-ß/SMAD4 signalling: Impacts on apoptosis, autophagy and ion channels in supraventricular tachycardia.

To explore the underlying molecular mechanisms of supraventricular tachycardia (SVT), this study aimed to analyse the complex relationship between FLRT3 and TGF-ß/SMAD4 signalling pathway, which affects Na+ and K+ channels in cardiomyocytes. Bioinformatics analysis was performed on 85 SVT samples and 15 healthy controls to screen overlapping genes from the key module and differentially expressed genes (DEGs). Expression profiling of overlapping genes, coupled with Receiver Operating Characteristic (ROC) curve analyses, identified FLRT3 as a hub gene. In vitro studies utilizing Ang II-stimulated H9C2 cardiomyocytes were undertaken to elucidate the consequences of FLRT3 silencing on cardiomyocyte apoptosis and autophagic processes. Utilizing a combination of techniques such as quantitative reverse-transcription polymerase chain reaction (qRT-PCR), western blotting (WB), flow cytometry, dual-luciferase reporter assays and chromatin immunoprecipitation polymerase chain reaction (ChIP-PCR) assays were conducted to decipher the intricate interactions between FLRT3, the TGF-ß/SMAD4 signalling cascade and ion channel gene expression. Six genes (AADAC, DSC3, FLRT3, SYT4, PRR9 and SERTM1) demonstrated reduced expression in SVT samples, each possessing significant clinical diagnostic potential. In H9C2 cardiomyocytes, FLRT3 silencing mitigated Ang II-induced apoptosis and modulated autophagy. With increasing TGF-ß concentration, there was a dose-responsive decline in FLRT3 and SCN5A expression, while both KCNIP2 and KCND2 expressions were augmented. Moreover, a direct interaction between FLRT3 and SMAD4 was observed, and inhibition of SMAD4 expression resulted in increased FLRT3 expression. Our results demonstrated that the TGF-ß/SMAD4 signalling pathway plays a critical role by regulating FLRT3 expression, with potential implications for ion channel function in SVT.

Drugs associated with a risk of supraventricular tachycardia: analysis using the OpenVigil database.

OBJECTIVE: The OpenVigil database can be used to assess medications that may cause supraventricular tachycardia (SVT) and to produce a reference for their safe use in clinical settings. METHODS: We analyzed first-quarter data from 2004 to 2023, obtained by searching the OpenVigil database using the keyword "supraventricular tachycardia." Trade names and generic names were obtained by querying the RxNav database, and the proportions were summarized. The proportionate reporting ratio (PRR), reporting odds ratio, and chi-square values were also summarized. We created Asahi diagrams and set the screening criteria to drug events ≥30, PRR >2, and chi-square >4. Outcomes were evaluated using the Side Effect Resource database, several scientific literature databases, and the Hangzhou Yiyao Rational Medication System. RESULTS: A total of 2435 distinct medications were found to induce SVT between the first quarter of 2004 and 2023, leading to 22,375 documented adverse events related to SVT. Further investigation revealed that salbutamol, paroxetine, formoterol, paclitaxel, venlafaxine, and theophylline were most likely to cause SVT. CONCLUSION: We conducted signal mining of adverse drug events using the OpenVigil database and evaluated the six drugs most likely to cause SVT. The results of this research can serve as a drug safety reference in the clinic.

SuperMap algorithm: an efficient, safe and accurate modality for mapping and eliminating challenging cardiac arrhythmias.

Even with the development of advanced catheter-based mapping systems, there remain several challenges in the electrophysiological evaluation and elimination of atrial arrhythmias. For instance, atrial tachycardias with irregular rates cannot be reliably mapped by systems that require stability in order to sequentially gather data points to be organized thereafter. Separately, these arrhythmias often arise following initial ablation for atrial fibrillation, posing logistic challenges. Here, we present the available literature summarizing the use of a non-contact mapping catheter, the AcQMap catheter, in conjunction with SuperMap, an algorithm that compiles a large number of non-contact data points from multiple catheter positions within the atria. These studies demonstrate the efficiency, safety and accuracy of this technology.

Irregular heart rhythms (arrhythmias) are often treatable with medications, but sometimes require expert evaluation in a cardiac electrophysiology laboratory. They are often studied and treated using thin, flexible catheters which enter the body through blood vessels in the leg and reach the internal walls of the heart. Time, expertise and specialized equipment are necessary to identify characteristics specific to each patient's arrhythmia. For each arrhythmia, a unique electrical blueprint is created before trying to eliminate it. The fleeting nature of certain arrhythmias can make it difficult to generate these blueprints, and many take a lot of time to accurately identify, leading to procedural challenges. Here we evaluate studies discussing the use of a new catheter (AcQMap) and its accompanying strategy for identifying arrhythmias. Unlike traditional catheters that require direct contact with the internal walls of the heart, the AcQMap catheter floats within these blood-filled chambers and does not touch the walls when obtaining data points. Instead, using ultrasound waves and electrical signals, it can generate data points to create blueprints. This technology also uses a new algorithm that enables the catheter to move freely within the heart, obtaining numerous data points and grouping them together to create maps efficiently and safely, even for fleeting or challenging arrhythmias.

[Historical developments in the diagnosis and treatment of pre-excitation syndromes (WPW)]. / Historische Entwicklung in Diagnostik und Therapie bei Präexzitationssyndromen (WPW).

In 1930, Wolff, Parkinson and White described the syndrome that bears their names. The mechanisms of supraventricular tachycardias were analyzed by brilliant electrocardiography interpretation by Pick and Langendorf. Wellens and Durrer using electrophysiologic studies analyzed the tachycardia mechanism invasively. In Germany the group by Seipel and Breithardt as well as Neuss and Schlepper studied the tachycardia mechanisms and response to antiarrhythmic drugs invasively by electrophysiological studies. Following the first successful interruption of an accessory pathway by Sealy in 1967, surgeons and electrophysiologists cooperated in Germany. Two centers, Hannover and Düsseldorf were established. Direct current (DC) ablation of accessory pathways was introduced by Morady and Scheinman. Because of side effects induced by barotrauma of DC, alternative strategies were studied. In 1987, radiofrequency ablation was introduced and thereafter established as curative therapy of accessory pathways in all locations.

Catheter ablation for supraventricular tachycardia and health resource utilization and expenditures: A propensity-matched cohort study.

BACKGROUND: Few data are available regarding temporal patterns of health resource utilization (HRU) and expenditures among patients undergoing catheter ablation for paroxysmal supraventricular tachycardia (PSVT). This study aimed to describe expenditures and HRU in patients with PSVT who underwent catheter ablation compared to a matched cohort of patients on medical therapy alone. METHODS: Using a large US administrative database, we identified adult patients (age 18 to 65 years) with a new PSVT diagnosis between 2008 and 2016. Propensity-score matching was used to assemble a PSVT cohort treated with ablation or medical therapy alone (N = 2556). Longitudinal trends in HRU and expenditures in the 3-years preceding and following PSVT diagnosis were compared. RESULTS: There were no significant differences in expenditures between groups except within the first year after PSVT diagnosis: $48,004 ablation vs. $17,560 medical therapy (p < 0.001). This difference was driven by procedural expenditures, where the mean cost of catheter ablation was $32,057 ± SD 26,737. In Years 2 and 3 post-ablation, HRU and expenditures decreased to the levels associated with the medical therapy group, although fewer ablation patients required any prescription for beta-blockers, calcium channel blockers, or anti-arrhythmic drugs (32% ablation vs. 42% medical therapy group, p < 0.001). CONCLUSION: Catheter ablation reduces medication burden in PSVT, yet health resource use and expenditures were similar beyond 2 years post-ablation when compared to PSVT patients on medical therapy alone. Additional studies are required to better understand drivers of these sustained health expenditures, and barriers to achieving cost-savings for a potentially curative procedure.

Resource Use and Clinical Outcomes in Infants with Supraventricular Tachycardia Monitored with the Owlet Smart Sock.

OBJECTIVES: To describe the prevalence of Owlet Smart Sock (OSS) use in infants with supraventricular tachycardia (SVT) and associated demographic and clinical characteristics of users and to analyze the association of OSS use on medical resource use and clinical outcomes from emergency department (ED) encounters for SVT. STUDY DESIGN: This was a single-center, retrospective cohort study of infants with confirmed SVT from 2015 to 2022. OSS users and nonusers were compared across clinical and demographic parameters. Medical resource use (phone calls, office visits, ED visits) and outcomes (need for intensive care, length of stay, echocardiographic function, clinical appearance) were compared between OSS users and nonusers. RESULTS: Of 133 infants with SVT, OSS was used by 31 of 133 (23%), purchased before SVT diagnosis in 5 in 31 (16%) of users. No demographic difference was found between OSS users and nonusers. OSS users had more phone notes than nonusers, (P = .002) and more ED visits (P = .03), but the number of office visits and medication adjustments did not differ. During ED presentation, OSS users had better preserved left ventricular ejection fraction on echocardiogram (P = .04) and lower length of hospital stay by a mean 1.7 days (P = .02). CONCLUSIONS: OSS is used by a portion of infants with SVT. It is associated with more frequent phone calls and ED visits but lower length of stay and better-preserved cardiac function upon presentation.

Plain language summary of the safety and effectiveness of etripamil for atrioventricular-nodal-dependent supraventricular tachycardia: the RAPID study.

WHAT IS THIS SUMMARY ABOUT?: This is a plain language summary of a clinical research study called RAPID. The study looked at the potential for how safe and effective etripamil was at stopping an episode of rapid heartbeats in people with atrioventricularnodal-dependent supraventricular tachycardia (AV-node-dependent SVT). An episode is used to describe the period of time when a person experiences an abnormally very fast heartbeat. This was done by comparing an investigational drug called etripamil with a placebo, each administered via a rapidly acting nasal spray. AV-node-dependent SVT affects the rhythm of the heart, causing it to suddenly beat rapidly. The condition often requires medical treatment to help return the heart to its normal, healthy heartbeat pattern and speed, called 'sinus rhythm'. Researchers are looking at ways of improving the management of supraventricular tachycardias (SVT) by reducing the need for patients to attend an urgent care clinic, emergency ward or hospital for treatment. In the RAPID study, participants used a nasal spray containing either 70 mg etripamil or a placebo solution when they experienced an episode of SVT. The researchers wanted to know how long it took for each participant's rapid heartbeat to return to sinus rhythm after administering the etripamil or placebo nasal spray. Participants in the study were considered successfully treated if their heartbeats returned to sinus rhythm for at least 30 seconds within 30 minutes of using the nasal spray. Although 30 seconds may seem brief, it's medically important because it shows that a person's heartbeat has been temporarily stabilized and returned to normal functioning. WHAT WERE THE RESULTS?: Out of 99 people who used etripamil during an SVT episode, 63 participants (64%) experienced a return to sinus rhythm for at least 30 seconds within 30 minutes after using the nasal spray. In contrast, 26 out of 85 participants (31%) who used the placebo nasal spray experienced a return to sinus rhythm for at least 30 seconds within 30 minutes after use. Furthermore, the average time taken for the return to sinus rhythm was 17 minutes for the etripamil group which was 3-times faster than the placebo group at 53 minutes. Also, in the study no serious side effects occurred that were related to etripamil. WHAT DO THE RESULTS OF THE STUDY MEAN?: The RAPID study supports the potential that etripamil may be safe and well tolerated by participants as a treatment for episodes of rapid heartbeat in people with AV-node-dependent SVT. The results also showed a significant improvement in symptoms following treatment with etripamil.

[Esophageal-ECG in the emergency department]. / ABC om Esofagus-EKG.

The management of tachycardias depends on their underlying pathophysiology. The key to uncovering this pathophysiology is in finding the temporal relationship between atrial and ventricular activation. The P-waves resulting from atrial activation can however be hard to detect on a traditional EKG in the setting of a tachycardia. Esophageal-EKG can help reveal the P-waves. The patient swallows an electrode, whose position in the esophagus is then adjusted to maximize the signal coming from the left atrium, clearly revealing atrial activity. This article describes the indications and contraindications for esophageal-EKG, as well as how it is performed and interpreted. Esophageal-EKG is of particular diagnostic value in the setting of a regular tachycardia with wide QRS complexes and no obvious signs of atrio-ventricular dissociation. In this setting, the esophageal-EKG can distinguish between ventricular tachycardia and a supraventricular tachycardia with aberrant conduction.

Comparing the effects of pulsed and radiofrequency catheter ablation on quality of life, anxiety, and depression of patients with paroxysmal supraventricular tachycardia: a single-center, randomized, single-blind, standard-controlled trial.

BACKGROUND: Radiofrequency catheter ablation (RFCA) may lead to decreased quality of life (QOL) and increased anxiety and depression in patients with paroxysmal supraventricular tachycardia (PSVT), possibly due to the lack of selectivity of the ablation tissue and the long ablation time. In recent years, pulsed field ablation (PFA) has been used for the first time in China to treat PSVT patients because of its ability to ablate abnormal tissue sites in a precise and transient manner. This study was conducted to compare the effects of PFA and RFCA on QOL and psychological symptoms of PSVT patients. METHODS: We have designed a single-center, randomized, single-blind, standard-controlled trial. A total of 50 participants who met the eligibility criteria would be randomly allocated into the PFA group or RFCA group in a 1:1 ratio. All participants were assessed using the 36-Item Short-Form Health Survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS) at pre-procedure (T0), post-procedure (T1), and 3 months post-procedure (T2). The SPSS 21.0 software was used to analyze the data through Wilcoxon and Fisher's exact tests and repeated measures ANOVA. RESULTS: Twenty-five in the PFA group and 24 in the RFCA group completed the trial. SF-36: (1) Between-group comparison: At T1, PFA group had significantly higher SF-36 scores on physiological function (PF) and general health (GH) than RFCA group, with a treatment difference of 5.61 points and 18.51 points(P < 0.05). (2) Within-group comparison: We found that in the PFA and RFCA groups, T2 showed significant improvement in the remaining 6 subscales of the SF-36 scale compared to T1 and T0 (P < 0.05), except for body pain (BP) and social function (SF) scores. HADS: (1) Between-group comparison: no significant difference (P > 0.05). (2) Within-group comparison: The HADS scores of the PFA and RFCA groups were statistically significant at T2 compared to T0 and T1 (P < 0.05). CONCLUSIONS: Our study provided new and meaningful evidence that PFA was effective in significantly improving QOL and decreasing anxiety and depression in PFA patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200060272.

Incidental Arrhythmias During Atrial Fibrillation Screening With Repeat 7-Day Holter ECGs in a Hospital-Based Patient Population.

BACKGROUND: Screening for atrial fibrillation (AF) may reveal incidental arrhythmias of relevance. The aim of this study was to describe incidental arrhythmias detected during screening for AF in the STAR-FIB (Predicting SilenT AtRial FIBrillation in Patients at High Thrombembolic Risk) cohort study. METHODS AND RESULTS: In the STAR-FIB cohort study, we screened hospitalized patients for AF with 3 repeat 7-day Holter ECGs. We analyzed all Holter ECGs for the presence of the following incidental arrhythmias: (1) sinus node dysfunction, defined as sinus pause of ≥3 seconds' duration; (2) second-degree (including Wenckebach) or higher-degree atrioventricular block (AVB); (3) sustained supraventricular tachycardia of ≥30 seconds' duration; and (4) sustained ventricular tachycardia of ≥30 seconds' duration. We furthermore report treatment decisions because of incidental arrhythmias. A total of 2077 Holter ECGs were performed in 794 patients (mean age, 74.7 years; 49% women), resulting in a mean cumulative duration of analyzable ECG signal of 414±136 hours/patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were sinus node dysfunction in 14 patients (1.8%), AVB in 41 (5.2%), supraventricular tachycardia in 42 (5.3%), and ventricular tachycardia in 2 (0.3%). Second-degree AVB was found in 23 patients (2.9%), 2:1 AVB in 10 (1.3%), and complete AVB in 8 (1%). Subsequently, 8 patients underwent pacemaker implantation, 1 for sinus node dysfunction (post-AF conversion pause of 9 seconds) and 7 for advanced AVB. One patient had an implantable cardioverter-defibrillator implanted for syncopal ventricular tachycardia. CONCLUSIONS: Incidental arrhythmias were frequently detected during screening for AF in the STAR-FIB study and resulted in device therapy in 1.1% of our cohort patients.

Cannon A wave validation as a diagnostic tool in paroxysmal supraventricular tachycardias.

OBJECTIVE: The presence of cannon A waves, the so called "frog sign", has traditionally been considered diagnostic of atrioventricular nodal re-entrant tachycardia (AVNRT). Nevertheless, it has never been systematically evaluated. The aim of this study is to assess the independent diagnostic utility of cannon A waves in the differential diagnosis of supraventricular tachycardias (SVTs). METHODS: We prospectively included 100 patients who underwent an electrophysiology (EP) study for SVT. The right jugular venous pulse was recorded during the study. In 61 patients, invasive central venous pressure (CVP) was registered as well. CVP increase is thought to be related with the timing between atria and ventricle depolarization; two groups were prespecified, the short VA interval tachycardias (including typical AVNRT and atrioventricular reciprocating tachycardia (AVRT) mediated by a septal accessory pathway) and the long VA interval tachycardias (including atypical AVNRT and AVRT mediated by a left free wall accessory pathway). RESULTS: The relationship between cannon A waves and AVNRT did not reach the statistical significance (OR: 3.01; p = .058); On the other hand, it was clearly associated with the final diagnosis of a short VA interval tachycardia (OR: 10.21; p < .001). CVP increase showed an inversely proportional relationship with the VA interval during tachycardia (b = -.020; p < .001). CVP increase was larger in cases of AVNRT (4.0 mmHg vs. 1.2 mmHg; p < .001) and short VA interval tachycardias (3.9 mmHg vs. 1.2 mmHg; p < .001). CONCLUSION: The presence of cannon A waves is associated with the final diagnosis of short VA interval tachycardias.

[Development of catheter ablation of supraventricular tachycardias with special consideration of contributions from German engineers and electrophysiologists]. / Entwicklung der Katheterablation supraventrikulärer Tachykardien unter besonderer Berücksichtigung der Beiträge deutscher Ingenieure und Elektrophysiologen.

The development and clinical implementation of catheter ablation of supraventricular tachycardia is one of the outstanding achievements of modern cardiovascular treatment. Over a period of less than 40 years, a curative and safe treatment strategy for almost all forms of atrial arrhythmias has been developed and implemented. German electrophysiologists and engineers have made a significant contribution to this truly outstanding success story in modern medicine. Their contributions should be appropriately acknowledged because without them, the development of ablation technology and its worldwide dissemination would not have been possible. Both the technological contributions and the medical-electrophysiological contributions were at the absolute forefront of worldwide developments and have made a significant contribution to the fact that today more than 500,000 patients with symptomatic and/or threatening cardiac arrhythmias can be successfully treated every year by use of catheter ablation. We would like to thank them all for their achievements.

[History of surgical treatment of cardiac arrhythmias in Germany : Surgical treatment of ventricular tachycardia and supraventricular tachycardia, especially pre-excitation syndromes (WPW)]. / Geschichte der chirurgischen Behandlung von Herzrhythmusstörungen in Deutschland : Chirurgische Therapie ventrikulärer Tachykardien sowie supraventrikulärer Tachykardien, insbesondere Präexzitationssyndromen (WPW).

The history of surgical treatment of ventricular tachycardias (VT) is short, lasting from 1978 until 1993. "Indirect procedures" with infarct scar resection were performed without electrophysiologic studies, whereas "direct procedures" consisted of either complete endocardial incisions ("encircling endocardial ventriculotomy") or large endocardial resections ("endocardial peel-off" technique) after precise epicardial and endocardial mapping procedures. In Germany, the first to report on intra-operative electrophysiologic mapping for VT treatment were Ostermeyer, Breithardt and Seipel in 1979. In 1981, the Hannover group (Frank, Klein) published their first results of surgical treatment of VT. In 1984, Ostermeyer et al. demonstrated that a partial endocardial incision resulted in more beneficial results with less myocardial damage (8% versus 46%) than applying a complete encircling incision. In 1987, the Düsseldorf group reported treatment results of 93 patients. After 5 years, 77% had no VT recurrence, while total mortality after 1 year was 11% and after 5 years 30%. In 1992, the Hannover group reported results of 147 patients after endocardial resection for VT. Total mortality after 3 years was 27%; recurrence of VT events occurred in 18% of the surviving cohort.The history of surgical procedures for supraventricular tachycardia (SVT), in particular Wolff-Parkinson-White (WPW) syndrome, is even shorter than that of surgery for VT. As early as 1969, Sealy, Gallagher and Cox reported the first cases of surgical intervention for WPW syndrome via endocardial access in cardioplegic arrest. In 1984, Guiraudon and Klein reported on a new procedure with epicardial access to the accessory bundle without cardioplegia in laterally localised conduction pathways. In Germany, too, the groups in Düsseldorf (Ostermeyer, Seipel, Breithardt, Borggrefe) from 1980 and the Hannover group (Frank, Klein and Kallfelz) from 1981 performed surgical procedures for WPW syndrome. In 1987, Borggrefe reported on 18 patients with WPW syndrome and atrial fibrillation who had undergone surgery. After 2 years, 14 of 18 patients had no recurrences of tachycardia; in 1989, Frank, Klein and Kallfelz (Hannover) reported on 10 children (2-14 years) operated on using the cryoablation technique. Between 1984 and 1992, a total of 120 patients with SVT, mostly WPW syndrome, were operated on in Hannover; after 42 months, 12 patients had a recurrence of SVT. Two patients died during the reoperation.