Brief report: the hemodynamic mechanism of pounding in the neck in atrioventricular nodal reentrant tachycardia

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.

Zero-fluoro atrioventricular-nodal reentrant tachycardia ablation

BACKGROUND

Atrioventricular-nodal reentrant tachycardia (AVNRT) is a common supraventricular tachycardia, particularly in younger patients. The treatment of choice is radiofrequency catheter ablation (RFCA), traditionally necessitating ionizing radiation for catheter guidance.

OBJECTIVE

The authors aimed to demonstrate the feasibility and safety of zero-fluoroscopy RFCA of AVNRT using EnSite™ NavX™ as a three-dimensional (3D) electroanatomical mapping system (EAM).

METHODS

The authors retrospectively analyzed 68 patients that underwent AVNRT-RFCA. One group was a priori allocated to conventional fluoroscopy mapping (convFluoro, n = 30). In 38 cases, the electrophysiologist chose to use 3D-EAM for ablation. Of these patients, 20 could be ablated without fluoroscopy use (zeroFluoro). In 18 cases that were initially intended as 3D-EAM, additional fluoroscopy use was necessary due to difficult anatomic conditions (convertedFluoro). Procedure duration, fluoroscopy duration and dose, as well as complications were analyzed.

RESULTS

Procedure duration was similar for the convFluoro and zeroFluoro groups (74 ± 24 min vs. 80 ± 26 min, p = ns). The convertedFluoro group showed longer procedure duration compared to the convFluoro group (94 ± 30 min vs. 74 ± 24 min, p < 0.05). The use of 3D-EAM significantly reduced fluoroscopy duration comparing the convFluoro with the convertedFluoro group (12 ± 9 min vs. 7 ± 6 min, p < 0.05). The difference in fluoroscopy dose between convFluoro and convertedFluoro did not reach significance (169 ± 166 cGycm2 vs. 134 ± 137 cGycm2, p = ns). In zeroFluoro cases, no radiation was used at all. 3D-EAM-guided RFCA was primarily successful in all patients. Overall, there were only few minor complications in the different groups. No major complications occurred.

CONCLUSION

Zero-fluoro RFCA in patients with AVNRT is feasible and safe. 3D-EAM can reduce radiation exposure in the majority of patients without prolonging procedure duration or increasing complications.

Reduction of Radiation Exposure in Atrioventricular Nodal Reentrant Tachycardia Ablations Using an Electroanatomical Mapping System With Fluoroscopy Integration Module

Introduction: Atrioventricular nodal reentrant tachycardia (AVNRT) is a common supraventricular tachycardia. Current guidelines recommend electrophysiology study (EPS) and ablation, which have been proven to show high success rates with very low complication rates. Usually, ablation of AVNRT is performed conventionally using only fluoroscopy. Electroanatomical mapping systems (EMS) are widely used in complex arrhythmias. One of their advantages is their potential in decreasing the need of fluoroscopy time (FT). In this study we analyzed patients undergoing either conventional AVNRT ablation or by using an EMS with a fluoroscopy integrating system (FIS).

Materials and Methods: We included 119 patients who underwent AVNRT ablation in our study. Eighty-nine patients were ablated conventionally using only fluoroscopy, 30 patients were ablated using EMS + FIS.

Results: We found that the use of EMS + FIS led to a significant reduction of FT (449.90 ± 217.21 vs. 136.93 ± 109.28 sec., p < 0.001) and dose-area-product (DAP, 268.27 ± 265.20 vs. 41.07 ± 27.89 μGym², p < 0.001) without affecting the procedure time (PT, 66.55 ± 13.3 vs. 67.33 ± 13.81 min, p = 0.783). Furthermore, we found no significance with regard to complications.

Conclusion: The use of EMS+FIS is safe and feasible. It leads to a significant reduction of both FT and DAP without affecting PT and safety. Hence, EMS + FIS is beneficial for both the operator and the patients by reducing the radiation exposure.

Differential diagnosis of wide QRS tachycardia: A review

Differential diagnosis of wide QRS tachycardia (WQRST) on the electrocardiogram remains a challenging exercise. Correct diagnosis is important for prescribing appropriate therapy and determining prognosis. Differential diagnosis of wide QRS tachycardia revolves around differentiation between supraventricular tachycardia with aberrant conduction and ventricular tachycardia. Observations such as clinical history, findings of physical examination during tachycardia, AV dissociation, QRS morphology in lead V1 and lead V6, precordial concordance, RS complexes in precordial leads, contralateral bundle branch block during wide QRS tachycardia, R wave morphologies in lead aVR, and ventricular initial/terminal velocity of conduction ratio can help arrive at the correct diagnosis with reasonable accuracy. The observations described here can help arrive at the correct diagnosis of WQRST with both reasonable accuracy and confidence.

Psychiatric Disorder and Incessant Tachyarrhythmia in a Child

The case of a 14-year-old female with ectopic atrial tachycardia who had been followed for a history of anxiety and depression is presented. The patient was admitted to the intensive care unit after she attempted suicide, at which point there was electrocardiographic evidence of the atrial arrhythmia. During subsequent invasive electrophysiology study, a focus near the tricuspid annulus was localized and targeted for ablation, followed by resolution of the psychiatric symptoms. The case highlights the overlap between psychiatric complaints and true cardiac arrhythmia. A review of the literature is presented, with a special emphasis on distinguishing these two entities as well as a synopsis of this uncommon arrhythmia in the pediatric population.

Test characteristics of neck fullness and witnessed neck pulsations in the diagnosis of typical AV nodal reentrant tachycardia

BACKGROUND

Claims in the medical literature suggest that neck fullness and witnessed neck pulsations are useful in the diagnosis of typical AV nodal reentrant tachycardia (AVNRT).

HYPOTHESIS

Neck fullness and witnessed neck pulsations have a high positive predictive value in the diagnosis of typical AVNRT.

METHODS

We performed a cross-sectional study of consecutive patients with palpitations presenting to a single electrophysiology (EP) laboratory over a 1 year period. Each patient underwent a standard questionnaire regarding neck fullness and/or witnessed neck pulsations during their palpitations. The reference standard for diagnosis was determined by electrocardiogram and invasive EP studies.

RESULTS

Comparing typical AVNRT to atrial fibrillation (AF) or atrial flutter (AFL) patients, the proportions with neck fullness and witnessed neck pulsations did not significantly differ: in the best case scenario (using the upper end of the 95% confidence interval (CI), none of the positive or negative predictive values exceeded 79%. After restricting the population to those with supraventricular tachycardia (SVT) other than AF or AFL, neck fullness again exhibited poor test characteristics; however, witnessed neck pulsations exhibited a specificity of 97% (95% CI: 90%-100%) and a positive predictive value of 83% (95% CI: 52%-98%). After adjustment for potential confounders, SVT patients with witnessed neck pulsations had a seven-fold greater odds of having typical AVNRT, p = 0.029.

CONCLUSIONS

Although neither neck fullness nor witnessed neck pulsations are useful in distinguishing typical AVNRT from AF or AFL, witnessed neck pulsations are specific for the presence of typical AVNRT among those with SVT.

Patient perception of symptoms and quality of life following ablation in patients with supraventricular tachycardia

OBJECTIVES

It remains unclear which symptom experiences and aspects of quality of life (QOL) change after ablation in patients with supraventricular tachycardia (SVT). To determine how patient perceptions of symptoms and QOL change after ablation, we used a single group pretest-posttest design.

METHODS

Patients with SVT (n=52; mean age 41+/-17 years; 65% female) completed generic and disease-specific measures at baseline and 1 month after ablation.

RESULTS

Significant improvement after ablation was noted on virtually all measures (P <.05). Patients reported decreases from baseline regarding frequency and duration of episodes, number of symptoms, and impact of SVT on routine activities. All symptoms decreased in prevalence; however, no symptoms were completely eliminated at 1-month follow-up. Women, more so than men, reported larger changes in symptom and QOL scores after ablation.

CONCLUSIONS

Despite the small sample, statistically significant improvement was found after ablation in a variety of patients with different symptoms and QOL indices.

Development and initial psychometric evaluation of the Patient Perspective of Arrhythmia Questionnaire

There are no disease-specific questionnaires to measure patient sensitive outcomes in arrhythmia patients. We report the development and preliminary psychometric testing of the Patient Perception of Arrhythmia Questionnaire (PPAQ). The PPAQ was developed using formative research, exploratory factor analysis, expert review, pilot study, and regression. The PPAQ measures frequency and duration of episodes, symptoms, impact on daily activities, and restricted activity days. After preliminary content validation, the sensitivity of the PPAQ was tested in 103 arrhythmia patients. The measures showed good sensitivity and reliability. Preliminary construct validation was supported by significant differences (p < .001) among groups of arrhythmia patients consistent with clinical patterns. Preliminary evidence from patients with supraventricular arrhythmias suggests that the questionnaire has acceptable psychometrics and could be useful in future studies of arrhythmia patients.

Simultaneous right atrioventricular pacing: a novel model to study atrial remodeling and fibrillation in the setting of heart failure

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia which contributes to morbidity and mortality in patients with heart failure (HF). Atrial remodeling is a key substrate for the development of AF in HF. However, experimental models that study AF in the setting of HF have important limitations. We evaluated a new dog model of atrial remodeling and AF.

METHODS AND RESULTS

Twenty-two mongrel dogs were randomized into 2 groups: 14 dogs with simultaneous atrioventricular pacing (SAVP) for 2 weeks (220 beats/min, no AV delay) and 8 control dogs with no pacing. SAVP for 2 weeks induced marked changes in atrial mechanical function and conduction. Left atrial area fractional shortening decreased 61 +/- 17%, whereas left ventricular area fractional shortening decreased by 38 +/- 18% from baseline (both P < .05). Conduction slowed and conduction heterogeneity increased. AF was induced in 83% of SAVP dogs, lasting a median of 1600 seconds, versus no dogs with induced AF in the controls. SAVP significantly increased nonfibrillar collagen in the mid-myocardium of both atrial appendages and matrix metalloproteinase-9 activity.

CONCLUSIONS

SAVP in dogs induces structural and electrical remodelling that form the substrate for reproducibly inducible AF. This novel model may be useful for studies of the pathophysiology and treatment of AF in heart failure.

Supraventricular tachycardia and the struggle to be believed

BACKGROUND

Little research exists examining patient experiences of life with supraventricular tachycardia (SVT). Realistic expectations of symptoms, patient management strategies, and treatment options are important components of patient education and treatment decisions.

AIM

This descriptive qualitative study explored patients' experiences living with SVT.

METHODS

Grounded theory methodology was used with semi-structured interviews of 25 SVT patients undergoing radiofrequency ablation treatment.

RESULTS

The main core category that emerged from the data was the "struggle to be believed". The struggle or work of living with SVT entails: (1) living with the uncertainty of the occurrence and duration of an episode, (2) "covering up" to manage symptoms and appear normal, (3) searching for causative factors to prevent further episodes, and (4) experimenting with management techniques to shorten or end episodes.

CONCLUSION

Clinical diagnosis and referral for ablation treatment were more difficult for women suggesting existence of a gender bias. As with many other chronic conditions, the illness trajectory work is formidable. Patients in this study with SVT, however, reported facing the additional difficulty of being believed. Disruptions in self-esteem and personal relationships are the effects of not being believed. Providers could avoid minimizing women's symptoms by listening seriously and offering realistic expectations; including insight into patient experiences and the trajectory of the dysrhythmia; and efficacy of drug and ablation treatments.

Acute Blood Pressure Changes After the Onset of Atrioventricular Nodal Reentrant Tachycardia: A Time-Course Analysis

INTRODUCTION

We aimed to characterize blood pressure (BP) response at the beginning of atrioventricular nodal reentrant tachycardia (AVNRT) and its relationship to orthostatic challenge and variable atrioventricular interval.

METHODS AND RESULTS

In this prospective study of 17 consecutive patients with documented AVNRT, mean BP was analyzed in the supine and upright positions during sinus rhythm, AVNRT, and pacing with atrioventricular delay of 150 msec (AV150) and 0 msec (AV0). Mean BPs were compared at 3-5 seconds, 8-10 seconds, and 28-30 seconds after the onset of AVNRT or pacing. BP decreased immediately after AVNRT initiation, with gradual recovery during the first 30 seconds from 71.9 +/- 16.5 mmHg to 86 +/- 13.8 mmHg, P < 0.01. A similar pattern was observed during AV0, but not during AV150, pacing. While supine, mean BP decrease was more pronounced during AVNRT and AV0 pacing (-26.1% and -32.1%, respectively) than during AV150 pacing (-8%, P = 0.02 and P = 0.07, respectively). This difference subsided 30 seconds after the onset of AVNRT or pacing. When upright, the mean BP time course was similar, but mean BP recovery during AVNRT was slower, and the difference between mean BP during AVNRT and AV150 persisted at 30 seconds.

CONCLUSIONS

The initial mean BP decrease during AVNRT recovered gradually within 30 seconds. A short atrioventricular interval is associated with a greater mean BP decrease at the onset of tachycardia. These observations may explain clinical symptoms immediately after the onset of AVNRT.

Effect of P-wave timing during supraventricular tachycardia on the hemodynamic and sympathetic neural response

BACKGROUND

Previous studies have shown the importance of the timing of atrial and ventricular systole on the hemodynamic response during supraventricular tachycardia (SVT). However, the reflex changes in autonomic tone during SVT remain poorly understood.

METHODS AND RESULTS

Eleven patients with permanent dual-chamber pacemakers were enrolled in the study. Arterial blood pressure (BP), central venous pressure (CVP), and peripheral muscle sympathetic nerve activity (SNA) were recorded during DDD pacing at a rate of 175 bpm (cycle length 343 ms) with an atrioventricular (AV) interval of 30, 200 and 110 ms, simulating tachycardia with near-simultaneous atrial and ventricular systole, short-RP tachycardia (RP<PR), and long-RP tachycardia (RP>PR). Each pacing run was performed for 3 minutes separated by a 5-minute recovery period. All patients demonstrated an abrupt fall in BP, an increase in CVP, and an increase in SNA regardless of the AV interval. The decreases in SBP, DBP, and MAP and the increase in CVP were significantly less during long-RP tachycardia (AV interval 110 ms) than during the other 2 pacing modes (P:<0.05), and the increase in SNA in 7 of the 11 patients was significantly greater during closely coupled atrial and ventricular systole than during long-RP tachycardia (P:<0.05).

CONCLUSIONS

These data suggest that the superior maintenance of hemodynamic stability during long-RP tachycardia is accompanied by reduced sympathoexcitation, which is primarily mediated by the arterial baroreceptors, with a modest cardiopulmonary vasodepressor effect.

Atrioventricular nodal versus atrioventricular supraventricular reentrant tachycardias: characterization by an integrated Doppler electrophysiological hemodynamic study

During reentrant supraventricular tachycardias involving the atrioventricular node (AVN-SVT) or an AV bypass tract (AV-SVT), atrial pressure increases. While in AVN-SVT this increase relates to atrial contraction during ventricular systole, the mechanism remains unclear in AV-SVT. This study sought to clarify this mechanism. During 11 AVN-SVTs and 9 AV-SVTs, anterograde flow through the AV valves and retrograde flow in the pulmonary and hepatic veins were studied by pulsed-wave (PW) Doppler measuring the time interval between the ECG-R wave and (1) the end of venous retrograde flows, and (2) the beginning of valvular anterograde flows. The positive or negative difference between these two time intervals guided recognizing the atrial contraction against open or closed AV valves. Intracavitary pressures and cardiac index were also measured. During AVN-SVTs, venous retrograde flows always ended before the anterograde valvular flows, indicating atrial contraction against closed AV valves. During AV-SVTs, pulmonary retrograde flow ended before the beginning of mitral anterograde flow in five cases, began before but ended during the anterograde flow in three cases, and overlapped to the anterograde flow in one case. A corresponding behavior was observed at the right side of the heart. In both SVTs, atrial pressures increased and end-diastolic ventricular pressure and cardiac index decreased similarly. During AVN-SVT, the atrial contraction always occurs against closed AV valves, and during AV-SVT it generally occurs against totally or partially closed AV valves, explaining similar atrial pressure and cardiac index changes in both SVTs.

Supraventricular tachycardia: implications for the intensivist

The critical care physician must have a keen awareness of supraventricular tachycardia patterns, mechanisms, precipitants, and treatment. Although long-term management of most forms of supraventricular tachycardia lies primarily in the realm of the cardiac electrophysiologist, the intensivist must be proficient at acute arrhythmia therapy. Expertise in electrocardiography, pharmacokinetics, and pharmacodynamics is essential. Careful assessment of hemodynamics and prudent bedside clinical acumen help assure optimal patient outcomes.

Atrial and ventricular pressures in atrial flutter

The hemodynamic effects of atrial flutter (AF) are unknown. The purpose of the present study was to investigate the changes in atrial and ventricular pressures after induction of AF. In 23 patients with paroxysmal AF (age 59 +/- 9 years), a hemodynamic study was performed both during sinus rhythm and after induction of the tachyarrhythmia. During AF, 13 patients showed a fixed 2:1 AV conduction and 10 patients showed variable conduction. Mean right and left atrial pressures increased (P < 0.001) and right and left ventricular end-diastolic pressures decreased (P < 0.001) after induction of AF. Both the increase in mean atrial pressures and the decrease in ventricular end-diastolic pressures were present either in the patients with fixed 2:1 AV (heart rate: 133 +/- 15 beats/min) or in those with variable conduction (heart rate 96 +/- 15 beats/min), but were more marked in the former. AF produces an impairment of atrial function, as evidenced by the increase in mean atrial pressures and reduction in ventricular end-diastolic pressures in the absence of an elevated heart rate. The mechanisms responsible for the increase in mean atrial pressures are unknown; however, atrial contractions against closed AV valves seem to play an important role.

Neck pounding during sinus rhythm: a new clinical manifestation of dual atrioventricular nodal pathways

OBJECTIVE

To determine the clinical and electrophysiological characteristics of patients with paroxysmal palpitations and neck pounding during sinus rhythm.

METHODS

Clinical, electrocardiographic, and electrophysiological characteristics of six patients with paroxysmal palpitations and neck pounding during sinus rhythm were studied in basal conditions and when symptomatic. Response to treatment was observed.

RESULTS

Baseline ECGs were normal (four patients) or had first degree atrioventricular block with intermittent PR shortening. During symptoms, narrow QRS rhythms were seen without visible P waves (three patients) or with P waves partially hidden in the QRS complex (three patients). Dual atrioventricular nodal pathways were found in all five patients who had electrophysiological studies. In these patients the slow pathway conduction time was long enough (mean (SD), 425 (121) ms) for ventricular activation after slow pathway conduction during sinus rhythm to coincide with the next atrial depolarisation, causing neck pounding during exercise (four patients) or at rest (two patients). Tachycardia was not induced in any patient. Medical treatment aggravated symptoms in three patients. A pacemaker was successfully used in two.

CONCLUSIONS

Neck pounding during sinus rhythm is a clinical manifestation of dual atrioventricular nodal pathways. Medical treatment may aggravate symptoms but a pacemaker may offer definitive relief.

Recognition and Management of Cardiac Arrhythmias: Part I. General Principles and Supraventricular Tachyarrhythmias

Management of cardiac arrhythmias has undergone major changes in the last few years. In the first part of this review, general principles of arrhythmia diagnosis are discussed. New techniques such as event recording and signal-averaged electrocardiography have a significant role in the clinical management of arrhythmias. Many new antiarrhythmic drugs are now available. Suppression of premature ventricular contractions to prevent malignant ventricular arrhythmias has been demonstrated to be an ineffective strategy. Implantable defibrillators and radio frequency ablation have revolutionized the treatment of arrhythmias. Differentiation of various supraventricular tachycardias has become very important since some these arrhythmias may be cured by radiofrequency ablation. Diagnosis and treatment of common supraventricular arrhythmias are discussed.

Neurohumoral and hemodynamic mechanisms of diuresis during atrioventricular nodal reentrant tachycardia

Thirty-two consecutive patients with paroxysmal supraventricular tachycardias, with previously defined mechanisms of the tachycardias, were interviewed by noninvestigators about whether they experienced symptoms of diuresis during or at the termination of the tachycardias, to test the hypothesis that patients with AV nodal reentrant tachycardia would have a feeling of diuresis, polyuria, or both during or at the termination of the tachycardia. Twelve of the 13 patients with AV nodal reentrant tachycardia (92%), two of the 15 patients with AV reentrant tachycardia (13%), and one of the 4 patients with atrial flutter associated with 2:1 AV conduction (25%) felt diuresis during or at the termination of the tachycardias (AV nodal reentrant tachycardia vs other forms of tachycardia; P < 0.001). In 14 of the 32 patients, the right atrial pressure and plasma atrial natriuretic peptide (ANP) concentration were measured during both the tachycardias and sinus rhythm. The mean right atrial pressure during AV nodal reentrant tachycardia was significantly elevated compared to that during other forms of tachycardia (P < 0.01). The plasma ANP concentration during AV nodal reentrant tachycardia was also elevated significantly compared to that during other forms of tachycardias (P < 0.001). There were no significant differences in the cycle lengths of the tachycardias, age, left atrial dimensions, or the left ventricular ejection fraction between the AV nodal reentrant tachycardia and the other forms of tachycardia. We concluded that the feeling of diuresis during or at the termination of tachycardia was a more common symptom in patients with AV nodal reentrant tachycardia. The higher secretion of plasma ANP from the right atrium might be involved in the mechanism of this symptom.

Effects of intravenous propranolol on cardiovascular hemodynamics during supraventricular tachycardia

Hemodynamic variables were evaluated in 10 patients during supraventricular tachycardia before and after administration of intravenous propranolol. The drug markedly worsened the already compromised hemodynamic pattern of supraventricular tachycardia.

Approach to the patient with palpitations

Palpitations are a common complaint present in up to 16% of outpatients. They are nonspecific and in only 15% of patients do they correlate with a cardiac arrhythmia. The significance of palpitations is related to the presence or absence of underlying cardiac disease, the clinical setting in which palpitations occur, and the characteristics and severity of symptoms. This article presents a concise approach to the evaluation of the ambulatory patient with palpitations.

Investigation of palpitations

The uncomfortable awareness of a beating heart--palpitations--is a common complaint that can occur under normal or abnormal circumstances. For example, normal palpitations occur with exercise, emotions, and stress, or after taking substances that increase adrenergic tone or diminish vagal activity (coffee, nicotine, and adrenergic or anticholinergic drugs). Normal palpitations are recognised as such because individuals who experience them realise or are told that something happened to accelerate the normal rhythm of the heart. However, some people find sinus tachycardia troublesome enough to seek medical attention. In other situations palpitations are clearly abnormal. The heart beat which is felt for no apparent reason, may be fast, or strong and slow, or feel like a missed or extra beat. Although these abnormal palpitations usually point to a cardiac arrhythmia, this is not always the case. Moreover, many patients with arrhythmias do not have palpitations but manifestations such as syncope, shock, and chest pain (sudden death is also possible). We will discuss the approach to the patient who seeks medical attention because of a history of palpitations, with special emphasis on the history, physical examination, and 12-lead electrocardiogram (ECG) because they are simple and inexpensive diagnostic tools that are available to most physicians.