Supraventricular Tachycardia DELACRETAZ, Etienne
The New England journal of medicine,
03/2006, Volume:
354, Issue:
10
Journal Article
Peer reviewed
A 28-year-old woman suddenly has rapid palpitations with dizziness while playing her cello. She is brought to an emergency department. She has a faint regular pulse of 190 beats per minute. Her blood ...pressure is 82/54 mm Hg. Cardiovascular examination reveals no signs of heart failure. An electrocardiogram shows a regular tachycardia with a narrow QRS complex and no apparent P waves. How should her case be managed?
A 28-year-old woman suddenly has rapid palpitations with dizziness while playing her cello. An electrocardiogram shows a regular tachycardia with a narrow QRS complex and no apparent P waves. How should her case be managed?
Foreword
This
Journal
feature begins with a case vignette highlighting a common clinical problem. Evidence supporting various strategies is then presented, followed by a review of formal guidelines, when they exist. The article ends with the author's clinical recommendations.
Stage
A 28-year-old woman suddenly has rapid palpitations accompanied by chest pain and dizziness while playing her cello. She is brought to an emergency department. She has a faint regular pulse of 190 beats per minute. Her blood pressure is 82/54 mm Hg. Cardiovascular examination reveals no signs of heart failure. An electrocardiogram shows a regular tachycardia with a narrow QRS complex and no apparent P waves. How should her case be managed?
The Clinical Problem
The term “supraventricular tachycardia” refers to paroxysmal tachyarrhythmias, which require atrial or atrioventricular nodal tissue, or both, for their initiation and maintenance. The incidence . . .
For patients having suffered ischemic stroke, the current diagnostic strategies often fail to detect atrial fibrillation as a potential cause of embolic events. The aim of the study was to identify ...paroxysmal atrial fibrillation in stroke patients. We hypothesized that patients with frequent atrial premature beats (APBs) recorded in 24-hour ECG will show more often atrial fibrillation when followed by repeated long-term ECG recordings than patients without or infrequent APBs.
127 patients with acute ischemic stroke and without known AF were enrolled in a prospective study to detect paroxysmal AF. Patients were stratified according to the number of APBs recorded in a 24-hour ECG (> or =70 APBs versus <70 APBs). Subsequently, they all underwent serial 7-day event-recorder monitoring at 0, 3, and 6 months.
Serial extended ECG monitoring identified AF in 26% of patients with frequent APBs but only in 6.5% when APBs were infrequent (P=0.0021). A multivariate analysis showed that the presence of frequent APBs in the initial 24-hour ECG was the only independent predictor of paroxysmal AF during follow-up (odds ratio 6.6, 95% confidence intervals 1.6 to 28.2, P=0.01).
In patients with acute ischemic stroke, frequent APBs (> or = 70/24 hours) are a marker for individuals who are at greater risk to develop or have paroxysmal AF. For such patients, we propose a diagnostic workup with repeated prolonged ECG monitoring to diagnose paroxysmal AF.
In patients with drug-resistant hypertension, chronic electric stimulation of the carotid baroreflex is an investigational therapy for blood pressure reduction. We hypothesized that changes in ...cardiac autonomic regulation can be demonstrated in response to chronic baroreceptor stimulation, and we analyzed the correlation with blood pressure changes. Twenty-one patients with drug-resistant hypertension were prospectively included in a substudy of the Device Based Therapy in Hypertension Trial. Heart rate variability and heart rate turbulence were analyzed using 24-hour ECG. Recordings were obtained 1 month after device implantation with the stimulator off and after 3 months of chronic electric stimulation (stimulator on). Chronic baroreceptor stimulation decreased office blood pressure from 185±31/109±24 mm Hg to 154±23/95±16 mm Hg (P<0.0001/P=0.002). Mean heart rate decreased from 81±11 to 76±10 beats per minute (P=0.001). Heart rate variability frequency-domain parameters assessed using fast Fourier transformation (FFT; ratio of low frequency:high frequency2.78 versus 2.24 for off versus on; P<0.001) were significantly changed during stimulation of the carotid baroreceptor, and heart rate turbulence onset was significantly decreased (turbulence onset−0.002 versus −0.015 for off versus on; P=0.004). In conclusion, chronic baroreceptor stimulation causes sustained changes in heart rate variability and heart rate turbulence that are consistent with inhibition of sympathetic activity and increase of parasympathetic activity in patients with drug-resistant systemic hypertension; these changes correlate with blood pressure reduction. Whether the autonomic modulation has favorable cardiovascular effects beyond blood pressure control should be investigated in further studies.
Between October 2015 and December 2016, 11,088 patients from 42 countries having cardiac resynchronisation therapy (CRT) devices implanted were included in the CRT II Survey. We compared the ...characteristics of Swiss CRT recipients with the overall European population.
Demographic and procedural data from seven Swiss centres recruiting all consecutive patients undergoing either de-novo CRT implantation or an upgrade to a CRT system were collected and compared with the European population.
A total of 320 Swiss patients (24.4% female, mean age 71.0 ± 10.2 years, 47% ischaemic cardiomyopathy) were enrolled, which amounts to 38% of all CRT implantations in Switzerland during this period. Of the patients enrolled, 38% had atrial fibrillation, 27% second- or third-degree atrioventricular block, and 68% complete left bundle-branch block. Swiss patients had significantly less often the classical indication of heart failure with a wide QRS complex (40 vs 61%; odds ratio OR 0.44, 95% confidence interval CI 0.35-0.55; p <0.001). Compared with the European population, Swiss patients were significantly older (71 vs 68.5 years, p <0.001), less symptomatic from heart failure and had more chronic kidney disease. Swiss patients significantly more often received a CRT-pacemaker (37 vs 30%; OR 1.37; 95% CI 1.09-1.73; p = 0.007) and quadripolar left ventricular leads (69 vs 57%; OR 1.67, 95% CI 1.32-2.13; p <0.001).
Compared with European CRT recipients, Swiss CRT patients are older, less symptomatic and suffer more often from comorbidities. Although two thirds of the implantations were CRT-defibrillator systems, Swiss patients more often received CRT-pacemaker systems than their European counterparts.
Abstract Background Recently, several cases of symptomatic and/or electrically detectable intracardiac inside-out abrasions in silicon-coated Riata® and Riata® ST leads have been described. However, ...the prevalence in asymptomatic patients with unremarkable implantable cardioverter defibrillator (ICD) interrogation is unknown. The aim of this study was to determine the prevalence of asymptomatic and electrically undetectable intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST leads. Methods All 52 patients with an active silicone-coated Riata® and Riata® ST lead followed up in our outpatient clinic were scheduled for a premature ICD interrogation and a biplane chest radiograph. When an intracardiac inside-out abrasion was suspected, this finding was confirmed by fluoroscopy. Results Mean time since implantation was 71 ± 18 months. An intracardiac inside-out abrasion was confirmed by fluoroscopy in 6 patients (11.5%). Mean time from lead implantation to detection of intracardiac inside-out abrasion was 79 ± 14 months. In all patients with an intracardiac inside-out abrasion, ICD interrogation showed normal and stable electrical parameters. Retrospectively, in 4 of these 6 patients, a coronary angiography performed 25 ± 18 months before diagnosis of intracardiac inside-out abrasion already showed the defect. Despite undetected intracardiac inside-out abrasion, 2 of these 4 patients experienced adequate antitachycardia pacing and ICD-shocks. ICD leads were replaced in all 6 patients. Conclusions The prevalence of asymptomatic intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST leads is higher than 10% when assessed by fluoroscopy, and most intracardiac inside-out abrasions are not detectable by ICD interrogation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary Background In patients with ventricular tachycardia (VT) and a history of myocardial infarction, intervention with an implantable cardioverter defibrillator (ICD) can prevent sudden cardiac ...death and thereby reduce total mortality. However, ICD shocks are painful and do not provide complete protection against sudden cardiac death. We assessed the potential benefit of catheter ablation before implantation of a cardioverter defibrillator. Methods The Ventricular Tachycardia Ablation in Coronary Heart Disease (VTACH) study was a prospective, open, randomised controlled trial, undertaken in 16 centres in four European countries. Patients aged 18–80 years were eligible for enrolment if they had stable VT, previous myocardial infarction, and reduced left-ventricular ejection fraction (LVEF; ≤50%). 110 patients were randomly allocated in a 1:1 ratio to receive catheter ablation and an ICD (ablation group, n=54) or ICD alone (control group, n=56). Randomisation was done by computer-generated randomly permuted blocks and stratified by centre and LVEF (≤30% or >30%). Patients were followed up for at least 1 year. The primary endpoint was the time to first recurrence of VT or ventricular fibrillation (VF). Analysis was by intention to treat (ITT). This study is registered with ClinicalTrials.gov , number NCT00919373. Findings 107 patients were included in the ITT population (ablation group, n=52; control group, n=55). Two patients (one in each group) withdrew consent immediately after randomisation without any follow-up data and one patient (ablation group) was excluded because of a protocol violaton. Mean follow-up was 22·5 months (SD 9·0). Time to recurrence of VT or VF was longer in the ablation group (median 18·6 months lower quartile 2·4, upper quartile not determinable) than in the control group (5·9 months IQR 0·8–26·7). At 2 years, estimates for survival free from VT or VF were 47% in the ablation group and 29% in the control group (hazard ratio 0·61; 95% CI 0·37–0·99; p=0·045). Complications related to the ablation procedure occurred in two patients; no deaths occurred within 30 days after ablation. 15 device-related complications requiring surgical intervention occurred in 13 patients (ablation group, four; control group, nine). Nine patients died during the study (ablation group, five; control group, four). Interpretation Prophylactic VT ablation before defibrillator implantation seemed to prolong time to recurrence of VT in patients with stable VT, previous myocardial infarction, and reduced LVEF. Prophylactic catheter ablation should therefore be considered before implantation of a cardioverter defibrillator in such patients. Funding St Jude Medical.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Atrioventricular (AV) conduction impairment is well described after surgical aortic valve replacement, but little is known in patients undergoing transcatheter aortic valve implantation (TAVI). We ...assessed AV conduction and need for a permanent pacemaker in patients undergoing TAVI with the Medtronic CoreValve Revalving System (MCRS) or the Edwards Sapien Valve (ESV). Sixty-seven patients without pre-existing permanent pacemaker were included in the study. Forty-one patients (61%) and 26 patients (39%) underwent successful TAVI with the MCRS and ESV, respectively. Complete AV block occurred in 15 patients (22%), second-degree AV block in 4 (6%), and new left bundle branch block in 15 (22%), respectively. A permanent pacemaker was implanted in 23 patients (34%). Overall PR interval and QRS width increased significantly after the procedure (p <0.001 for the 2 comparisons). Implantation of the MCRS compared to the ESV resulted in a trend toward a higher rate of new left bundle branch block and complete AV block (29% vs 12%, p = 0.09 for the 2 comparisons). During follow-up, complete AV block resolved in 64% of patients. In multivariable regression analysis pre-existing right bundle branch block was the only independent predictor of complete AV block after TAVI (relative risk 7.3, 95% confidence interval 2.4 to 22.2). In conclusion, TAVI is associated with impairment of AV conduction in a considerable portion of patients, patients with pre-existing right bundle branch block are at increased risk of complete AV block, and complete AV block resolves over time in most patients.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Because of the development of modern transportation facilities, an ever rising number of individuals including many patients with preexisting diseases visit high-altitude locations (>2500 ...m). High-altitude exposure triggers a series of physiologic responses intended to maintain an adequate tissue oxygenation. Even in normal subjects, there is enormous interindividual variability in these responses that may be further amplified by environmental factors such as cold temperature, low humidity, exercise, and stress. These adaptive mechanisms, although generally tolerated by most healthy subjects, may induce major problems in patients with preexisting cardiovascular diseases in which the functional reserves are already limited. Preexposure assessment of patients helps to minimize risk and detect contraindications to high-altitude exposure. Moreover, the great variability and nonpredictability of the adaptive response should encourage physicians counseling such patients to adapt a cautionary approach. Here, we will briefly review how high-altitude adjustments may interfere with and aggravate/decompensate preexisting cardiovascular diseases. Moreover, we will provide practical recommendations on how to investigate and counsel patients with cardiovascular disease desiring to travel to high-altitude locations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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