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Biomedical subjects

A Pacifico

Publications and source records attributed to A Pacifico.

At least 55 records · Page 3Linked to original sources
PubMed1994

Frequency and significance of conduction defects early after orthotopic heart transplantation.

To define the clinical significance of conduction defects after orthotopic heart transplantation sequential electrocardiograms (ECG) of 124 patients were analyzed during their postoperative hospital stay. The first ECG was abnormal in 90 patients (73%), with a predominance of right bundle branch block, and normal in 34 (27%). Sex, age, mean donor ischemic time, duration of aortic cross clamping and use of previous antiarrhythmic therapy were not significantly different in the 2 groups. During hospital follow-up, patients were grouped according to evolution of the initial electrocardiographic abnormalities. In group 1, 25 patients continued to have an initially normal ECG. In groups 2 and 3, 30 and 48 patients, respectively, had evidence of transient and permanent conduction defects. The 21 patients in group 4 showed progressive deterioration of conduction with either a new (9 patients) or worsening preexisting conduction defect (12 patients). The evolution of the initial ECG was strongly dependent on the duration of the donor heart ischemic time and the severity of the in-hospital cardiac rejection. Patients with persistent conduction abnormalities had a statistically longer ischemic time than either patients with normal or transient conduction defects (182 +/- 84 vs 144 +/- 68 and 130 +/- 66 minutes, p = 0.04). Although the overall percentage of patients with histologic evidence of moderate to severe rejection was similar across the groups, 66.6 and 46.1% of patients in groups 3 and 4, respectively, had multiple episodes of rejection compared with 16.6 and 0% in the remaining 2 groups (p = 0.044).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Spectral analysis of activation time sequences.

Adequate spatial resolution of local activation is fundamental for the correct depiction of myocardial activation during ablative treatment of ventricular tachycardia. The widest allowable distances between recording sites that provide an accurate description of the field potential distribution is dictated by the Nyquist sampling theorem. Activation times are derived from the field potentials. However, because of noise intrinsic in activation detection algorithms, closer recording sites may be required than those theoretically computed. The purpose of this study is to examine the spatial frequency spectrum of epicardial activation time sequences computed by common activation detection algorithms, determine which algorithm is least noisy, and derive the recording site density necessary to avoid distortion of the epicardial activation map. Using 40 to 80 electrode linear arrays, monopolar and bipolar electrograms from the epicardium were recorded vertically (base to apex) and horizontally in 11 dogs. Activation times for bipolar electrograms were estimated using Peak, Fastest Zero Crossing, and Morphological algorithms. Activation times for monopolar electrograms were set equal to the time of the fastest negative deflection. Activation time sequences were analyzed using conventional Fourier techniques. Anomalous activation times from serially adjacent bipolar electrograms, which constitute algorithm noise, were studied. Horizontal and vertical interelectrode distances are 3.2 mm and 2.4 mm, respectively. Of the bipolar algorithms, the Morphological algorithm produced the fewest anomalous activation times. Mapping systems having more than 256 channels are required for accurate representation of epicardial activation in a typical 20-kg dog. The endocardial electrode spacing is unknown, but is expected to be at least as dense. Large global mapping systems or regionally dense arrays may offer advantages during catheter ablations for ventricular tachycardia and for studies into the mechanisms of ventricular tachycardia by accurately defining the cardiac activation pattern.

Algorithms↗
PubMed1993

Raised serum apolipoprotein (a) in active diabetic retinopathy.

Progressive capillary occlusion often leads to severe retinopathy within 15-20 years of the onset of Type 1 (insulin-dependent) diabetes mellitus. Lipoprotein(a), a complex formed by apolipoprotein(a), apo B-100 and lipids, is considered an independent, genetically determined, predictor of cardiovascular disease. It may have antifibrinolytic properties in view of its similarity to plasminogen. To test the hypothesis that circulating lipoprotein(a) is associated with the process that leads to clinically active diabetic retinopathy, we measured the circulating levels of apolipoprotein(a) (which are strictly correlated with those of lipoprotein(a)) in two groups of patients with Type 1 diabetes of at least 15 years duration: 25 with active retinopathy and 27 without clinically detectable retinal lesions. Thirty-eight healthy subjects of the same age and sex served as controls. Serum apolipoprotein(a) was higher in the patients with active retinopathy (36(2-193) U/dl, geometric mean and range) than in those without clinically detectable retinal lesion (17(1-160)) and the control subjects (14(0-115)), p < 0.01 in both cases. The distribution of apolipoprotein(a) levels was skewed to the left, as expected, in the patients without clinically evident retinal lesions and the control groups, but there was a bimodal trend of distribution among those with active retinopathy. The levels of glycated haemoglobin were similar in the two groups of diabetic patients, and no significant differences were found for total and HDL cholesterol, triglycerides or apolipoproteins A1 and B between them and the control subjects. These preliminary results suggest that serum apolipoprotein(a) is elevated in patients with active retinopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Simultaneously collected monopolar and discrete bipolar electrograms: comparison of activation time detection algorithms.

Designation of the time of local activation is fundamental to electrophysiological mapping. In normal myocardium, the minimum slope in extracellular monopolar (MP) electrograms has been linked through simultaneous intracellular and extracellular recordings to phase 0 of the action potential. However, no similar correlation has been demonstrated for a parameter from bipolar (BP) electrograms, now commonly used during electrophysiological studies and intraoperative mapping. The purpose of this work is to compare the activation time, determined according to several common algorithms applied to BP electrograms, with the time of the minimum slope in MP electrograms. Simultaneous normal epicardial MP and BP electrograms were acquired from subjects undergoing surgery for Wolf-Parkinson-White Syndrome and from dogs. The activation time in BP electrograms was defined by four algorithms: (1) peak (P); (2) greatest absolute slope (S); (3) zero crossing of the segment containing the greatest slope (FZC); and (4) morphological (M). Each was compared to the time of the minimum slope in the simultaneously recorded MP response. The incidence of outliers was tabulated. The distribution of activation times computed using each BP algorithm was statistically different from the distribution of activation times derived from MP electrograms. M performed best (absolute difference: 2.6 +/- 2.9 msec; cor coef: 0.9925 in man). The M, P, FZC, and S algorithms produced 3.2%, 3.5%, 4.7% and 4.7% outliers, respectively. The overall performance of a morphologically based algorithm is superior to simplistic BP algorithms based only on slope or peak.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗
PubMed1993

The epicardial field potential in dog: implications for recording site density during epicardial mapping.

Investigations into mechanisms and successful surgical therapy of ventricular tachycardia (VT) depend upon accurate endocardial/epicardial mapping. Deduction of local activation is based upon parameters derived from the field potential (FP) (monopolar recording) or its first spatial derivative (bipolar recording). Adequate electrode spacing is an assumption fundamental to the mapping process, but the electrode spacing required for accurate representation of the FP is unknown. The purpose of this work is to derive the electrode spacing necessary to accurately describe the FP on the epicardium. In 11 dogs, electrograms from vertical (V) (base to apex) bands having 40 electrodes and horizontal (H) bands having 40 to 80 electrodes were sampled at 1 kHz. The spatial bandwidths (BW) were computed according to two criteria: (1) the frequency yielding 2% mean squared error (MSE) computed at the time of the greatest integrated magnitudes of the Fourier transform; and (2) the highest frequency bounding 95% power computed at each msec throughout the beat. Implied electrode spacings were defined according to the sampling theorem. The 5th percentiles of the implied electrode spacing distributions were used to define the widest interelectrode distance required to prevent spatial aliasing. H-5th percentile and V-5th percentile were, respectively: 2% MSE (3.5 mm, 2.3 mm); 95% power (3.6 mm, 2.3 mm). Thus, a typical 20-kg dog requires more than 250 recording sites for accurate epicardial mapping. Extrapolating to man, these results suggest inadequate electrode density may partially be responsible for incomplete and ambiguous reentry patterns often observed during intraoperative mapping.

Animals↗
PubMed1993

Antiarrhythmic effects of selective prolongation of refractoriness. Electrophysiologic actions of sematilide HCl in humans.

BACKGROUND: Recent data have suggested that antiarrhythmic agents that act largely by delaying conduction may not be as effective in controlling ventricular arrhythmias as those that prolong repolarization. Recently, numerous "pure" class III agents have been developed. METHODS AND RESULTS: The antiarrhythmic and electrophysiologic profiles of sematilide, a "pure" class III agent, were determined in 27 patients with clinical ventricular arrhythmias and inducible sustained ventricular tachycardia during electrophysiologic study. After treatment with oral sematilide (mean dose, 133 +/- 29 mg every 8 hours), the patients underwent repeat 24-hour ambulatory ECG monitoring and electrophysiologic study. The baseline sinus cycle length and QT, QTc, JT, and JTc intervals were significantly increased 8 to 17% by sematilide (P = .001 to .029). There were no changes in the PR or QRS intervals. Sematilide (at a paced cycle length of 600 ms) significantly increased the atrial effective refractory period (238 +/- 32 to 264 +/- 32 ms; 11 +/- 16% increase from baseline; P = .013), atrioventricular nodal effective refractory period (296 +/- 74 to 354 +/- 71 ms; 20 +/- 19%; P = .029), and right ventricular effective refractory period (252 +/- 25 to 281 +/- 30 ms; 12 +/- 8%; P < .001) but did not significantly change the PA or HV intervals, the corrected sinus node recovery time, or the Wenckebach cycle length. Determination of the frequency-dependent effects of sematilide (n = 10) on the right ventricular monophasic action potential duration (APD90) during ventricular pacing at cycle lengths of 600 to 300 ms revealed that the APD90 was significantly prolonged by sematilide during ventricular pacing at 600 to 350 ms (APD90 increase of 40 +/- 17, 27 +/- 21, 18 +/- 18, and 14 +/- 15 ms, respectively) but not at 300 ms (APD increase of 13 +/- 19 ms). Sematilide significantly prolonged the APD90 to a greater degree at longer than at shorter cycle lengths (P = .02). The ventricular effective refractory period had a similar reverse frequency-dependent relation as the APD90. Sematilide had no effect on the ventricular effective refractory period-to-APD90 ratio or on ventricular conduction. Sematilide suppressed the induction of sustained ventricular tachycardia in 41% of all patients exposed to sematilide. Prolongation of ventricular refractoriness was correlated with ventricular tachycardia suppression. The right ventricular effective refractory period (at 600 ms) increased by 38 +/- 14 ms in patients whose sustained ventricular tachycardia was suppressed by sematilide and by 19 +/- 18 ms in patients not suppressed (P = .015). One patient developed short runs of pause-dependent nonsustained ventricular tachycardia. Eight patients were placed on long-term sematilide therapy, and during a mean follow-up period of 7.0 +/- 7.5 months, two patients developed sudden cardiac death, and one additional patient had recurrent sustained ventricular tachycardia. CONCLUSIONS: The electrophysiologic profile of sematilide is consistent with selective block of outward potassium currents and associated isolated lengthening of the ventricular effective refractory period and APD; sematilide demonstrates a significant degree of reverse frequency-dependence of the ventricular APD and effective refractory period; and suppression of ventricular tachycardia inducibility by sematilide appears to be correlated with increases in the right ventricular effective refractory period.

Anti-Arrhythmia Agents↗
PubMed1992

Long-term multicenter experience with a second-generation implantable pacemaker-defibrillator in patients with malignant ventricular tachyarrhythmias. The Guardian Multicenter Investigators Group.

A second-generation implantable pacemaker-cardioverter-defibrillator was evaluated in 200 patients with sustained ventricular tachycardia, ventricular fibrillation or prior cardiac arrest. The device permits demand ventricular pacing for bradyarrhythmias and for long QT interval or tachycardia suppression, uses programmable (3 to 30 J) energy shocks for conversion of ventricular tachycardia and ventricular fibrillation and is used with conventional pacing and defibrillation leads. Ventricular tachycardia/fibrillation recognition is based on the ventricular electrogram rate and requires reconfirmation before shock delivery. Two hundred patients (mean age 62 years, mean left ventricular ejection fraction 36%) were enrolled and followed up for 0 to 23 months (mean 12). Epicardial lead system implantation was performed with use of an anterolateral thoracotomy (38%), median sternotomy (26%) and subxiphoid (20%) or subcostal (16%) approach. Perioperative mortality rate was 5.5% (all nonarrhythmic deaths). Implant defibrillation threshold ranged from 3 to 30 J (mean 15), with initial programmed shock energy ranging from 3 to 30 J (mean 22). Ventricular tachycardia/fibrillation sensing threshold ranged from 0.7 to 1.8 mV (median 1) and the tachycardia detection interval from 288 to 416 ms (median 320). Reprogramming of implant variables was necessary for reliable electrographic sensing (54 patients), programmed shock therapy (61 patients) and tachycardia detection rate (63 patients). Device activation for potential shock delivery occurred in 111 patients (55.5%) with actual shock delivery after ventricular tachycardia/fibrillation reconfirmation in 66 patients (33%). During follow-up study, there was a 1% arrhythmia mortality rate, 6.5% cardiac mortality rate and 10.5% total mortality rate. This study demonstrates that the programmable implantable pacemaker-cardioverter-defibrillator is effective in preventing arrhythmic death, yet reduces patient exposure to repeated shock therapy. Reprogramming is usually necessary during follow-up for optimal function.

Adolescent↗
PubMed1992

Familial insulinoma: description of two cases.

We describe cases of isolated functioning insulinoma occurring in two members of the same family (father and daughter). The father had a first encapsulated insulinoma diagnosed at 14 years of age and at the age of 33 years he was operated on for a second insulinoma infiltrating the exocrine pancreas with lymph node metastases. The daughter was operated on for an encapsulated insulinoma in the tail of the pancreas when she was 6 years old. No clinical and laboratory signs of other endocrine disturbances have so far been detected in either care or in any other members of the family. Our report suggests the possibility of multiple familial insulinoma, although this is an extremely rare condition. Our data also indicate that insulinomas, even if well controlled by medical treatment, should always be removed by surgery because malignancy cannot be excluded with certainty. Moreover, patients should be closely followed up, as recurrence may develop up to 15 years after surgery.

Adolescent↗
PubMed1992

Observations on the epicardial activation of the normal human heart.

Serial hand mapping techniques in man have identified 3 to 5 sites of epicardial breaktrough (EBT). However, transmural epicardial excitation from the widely distributed His/Purkinje system suggests a more complicated pattern may exist. Multielectrode arrays used with large mapping systems during surgery often present complicated and sometimes inconsistent activation patterns. The purpose of this work is to reconcile epicardial activation in the normal human heart with anatomical and endocardial/intramural physiological recordings using multichannel computer mapping requiring only a single beat, and rigorously defined and applied activation time detection algorithms. Eighteen subjects undergoing surgery for Wolff-Parkinson-White syndrome were recorded with a 119 site sock array during nonpreexcited sinus rhythm. None had evidence of coronary artery disease and all exhibited a normal 12-lead ECG except during periods of preexcitation or tachycardia. Each was recorded bipolarly and four also were recorded monopolarly. Recordings revealed 8.0 +/- 1.6 EBTs (range 5 to 12). Closely spaced, multiple EBTs often were observed and usually confirmed using different activation time detection algorithms. The earliest EBT always occurred over the anterior right ventricle at 14.3 +/- 6.5 msec (range -1 to 29 msec) after QRS onset. Subsequent EBTs could occur at any ventricular site with variable latencies. In contrast to previous reports describing epicardial spread of activation from a few foci, a mosaic of epicardial activation emerges. These data are consistent with endocardially initiated transmural activation of the epicardium suggested by the anatomy of the His/Purkinje system and intramural recordings.

Algorithms↗
PubMed1991

The automatic implantable cardioverter-defibrillator: effect of patch polarity on defibrillation threshold.

An automatic implantable cardioverter-defibrillator (AICD) was implanted in 40 patients with sudden cardiac arrest (n = 29), sustained monomorphic ventricular tachycardia (n = 10) or recurrent syncope (n = 1) who were unsuitable for direct ablative surgery or had had unsuccessful medical therapy. The effect of patch electrode polarity on the defibrillation threshold was prospectively evaluated. Two large epicardial patches were used. Initial polarity was selected at random. Ventricular fibrillation was induced by direct current and a preestablished defibrillation protocol employed to assess the minimal energy that would reproducibly defibrillate the heart. Nineteen patients had a lower defibrillation threshold with the inferior left ventricular patch as an anode and nine patients had a lower defibrillation threshold with this patch as a cathode. In general, the defibrillation threshold was lower when this patch was used as an anode than when it was used as a cathode (18 +/- 10 versus 22.6 +/- 12.2 J; p less than 0.01). No preoperative variable predicted optimal polarity. Therefore, the effect of patch polarity on defibrillation threshold should be assessed in each patient at the time of AICD implantation so that the safety margin for satisfactory device function can be maximized.

Aged↗
PubMed1991

Late results of the left subcostal approach for automatic implantable cardioverter defibrillator implantation.

A left subcostal surgical approach was used to implant an automatic implantable cardioverter defibrillator (AICD) in 48 patients with a history of nonfatal cardiac arrest or documented ventricular tachycardia/fibrillation. Electrophysiologic studies before surgery yielded induction of monomorphic or polymorphic ventricular tachycardia in 40 patients, whereas 8 were noninducible. Mean (+/- standard deviation) age was 58 +/- 12 years. Mean ejection fraction was 33 +/- 16%. Thirty patients (63%) had documented coronary artery disease; 14 patients (29%) had previous coronary bypass surgery. The mean intraoperative defibrillation threshold was 13.8 +/- 6.6 J. In 6 patients, an adjunctive right minithoracotomy was used to position 1 patch over the right atrium and thus optimize the defibrillation threshold. Patients with prior exposure to amiodarone and previous coronary bypass surgery had higher defibrillation thresholds at implantation. Two perioperative deaths occurred. There were no infections. Long-term follow-up yielded a 1- and 5-year survival of 0.88 and 0.58, respectively, and a freedom from sudden cardiac death of 1.0 and 0.97, respectively. The nonthoracotomy, left subcostal surgical approach is safe and effective, provides adequate defibrillation thresholds in most patients, and yields long-term survival comparable to other implantation techniques.

Cardiac Pacing, Artificial↗
PubMed1991

Time course of creatine kinase release after termination of sustained ventricular dysrhythmias.

Differentiation between primary and secondary (caused by acute myocardial infarction) ventricular fibrillation has important therapeutic and prognostic implications. The diagnosis of myocardial infarction is based on clinical, ECG, and creatine kinase MB isoenzyme (MBCK) activity. Enzymatic criteria might not be able to confirm the diagnosis of myocardial infarction after recent cardioversion. The routine use of electrophysiologic studies involving the induction and termination of ventricular dysrhythmias provides a setting in which enzyme release as a result of cardioversion alone can be examined. Therefore a systematic investigation of the magnitude and time course of creatine kinase (CK) and MBCK release was performed after termination of ventricular dysrhythmias in 57 patients undergoing electrophysiologic studies. Of patients requiring external cardioversion, only 50% had an elevation in CK and MBCK activity. Elevation when present corrected with the number of shocks and cumulative energy delivered. The magnitude of MBCK release exceeded 10% of the total CK activity in 9% of observations. Pace-termination of ventricular tachycardia did not result in enzyme release. Arrhythmia characteristics, coronary artery disease, and left ventricular function did not affect the magnitude of the time course of enzyme release. These data suggest that cardioversion with multiple shocks may result in a component of MBCK release, and thus a false positive diagnosis of primary acute myocardial infarction may be made by relying exclusively on the enzyme release pattern.

Clinical Enzyme Tests↗
PubMed1991

Heterotopic heart transplantation and native heart ventricular arrhythmias.

Heterotopic heart transplantation has been said to be contraindicated in patients with serious native heart arrhythmias that produce hemodynamic instability. Placement of heterotopic allografts, however, can theoretically act as a biological biventricular assist device to provide hemodynamic support during these unstable rhythms. Further, this operation might beneficially alter the hemodynamic milieu of heart failure such that the arrhythmias are ameliorated. Described is our experience with 4 patients with heart failure receiving heterotopic cardiac allografts, documenting changes in native heart arrhythmia that occurred. These cases demonstrate that heterotopic grafts can adequately sustain hemodynamics during malignant native heart dysrhythmia. We believe native heart ventricular arrhythmias are not a contraindication to heterotopic heart transplantation.

Arrhythmias, Cardiac↗
PubMed1991

Bandwidth-induced errors in parameters used for automated activation time determination during computerized intraoperative cardiac mapping: theoretical limits.

Two parameters commonly used when determining the time of local activation during computerized intraoperative cardiac mapping are the time of the peak in bipolar electrograms (BP) and the time of the largest negative slope (LNS) in monopolar electrograms (MP). The dependence of these parameters upon bandwidth was studied. A database of fast MP and BP was compiled from intraoperative recordings collected from epicardial sock arrays in man. Based on 95%, 99% and 99.9% of total signal power, the bandwidths of each response were determined. After removing specified frequencies using the Fourier transform, errors in determining these parameters were computed and characterized with respect to mean square error (MSE), percent power bandwidth and frequency content. The Fourier transform was used to abruptly filter out undesired upper frequencies. Filtering BP at 200 Hz produced a 1-ms shift in the peak in 17.0% of the electrograms, 0.4% of the peaks shifted by 2 ms and none shifted by more than 2 ms. Comparable shifts in the LNS occurred when filtering MP at 400 Hz. Retention of 95% of the power in a BP rarely (0.9%) changed the time of its peak by more than 1 ms. For MP, retention of 99.9% of the power was required for similar performance (3.6%). Thus, although BP have greater signal power in the higher frequencies than MP, a greater bandwidth is required when recording monopolarly in order to preserve the small amount of power necessary to define the time of the LNS with accuracy comparable to determination of the peak in BP.

Analog-Digital Conversion↗
PubMed1991

Influence of time of sampling onset on parameters used for activation time determination in computerized intraoperative mapping.

The purpose of this work is to determine the sensitivity of the estimated time of peaks and maximum slopes, commonly used in activation time computations, to the instant at which sampling is initiated. Based on complex and quickly changing waveforms, 471 monopolar (MP) and bipolar (BP) epicardial responses in man were selected. These were decimated from 10 kHz to simulate sampling at frequencies ranging from 200 Hz to 2,000 Hz. The peak and maximum absolute slope for BP and the minimum slope for MP were computed repeatedly starting at successive 100 microseconds intervals extending throughout the sampling period and compared with these parameters computed from the waveform sampled at 10 kHz. Slopes were estimated using each of four different algorithms. The average greatest shift (AGS) due to variations in sampling onset ranged from 11.2 +/- 3.5 (200 Hz) to 0.3 +/- 0.2 msec (2,000 Hz). For bipolar algorithms, the peak performed better than the slope algorithms (AGS: 5.9 +/- 3.3 to 0.3 +/- 1.0 msec). For MP algorithms, 2 point linear, and 3 and 5 point Lagrange slope estimates performed similarly (AGS: 5.6 +/- 3.3 to 0.3 +/- 0.2 msec); a 5 point least square fit algorithm performed poorly. Sampling MP and BP electrograms below 500 and 400, respectively, often caused maximum shifts greater than 4 msec. Thus, the resolution of the peak and estimated slope is not limited to the sampling period, variations in initiation of sampling can cause significant outliers especially at low sampling rates, and MP electrograms should be sampled faster than BP electrograms for comparable accuracy.

Electrocardiography↗
PubMed1991

Design and implementation of a new computerized system for intraoperative cardiac mapping.

A rapid, portable, yet inexpensive and expandable computer-based system utilizing current technology has been developed from experience in the operating room. An efficient operating system well suited for surgery is defined. New technology recording arrays fabricated from multielectrode flexible Kapton strips were developed and found to be easy to use and highly reliable. Novel arrays are created easily for research or special clinical applications. The system displays all incoming data in real time and transfers 16-s epochs to disk on command. After the user defines a beat for analysis, the computer determines the activation time for each channel, rejects unsatisfactory channels, and displays the results for review and modification before plotting the isochronal map on the monitor. The average time to recall data and produce a map is 16 s; if manual review of 120 channels is included, mapping time is less than 4 min. Clinical data recorded during surgery are discussed. The speed and operational ease demonstrated in the operating room make this computer/electrode system valuable both for surgery and for elucidating basic mechanisms of arrhythmias.

Algorithms↗
PubMed1991

Resolution of ventricular tachycardia and endocardial tuberculoma following antituberculosis therapy.

A 23-year-old woman presented with sustained ventricular tachycardia and was found to have an endocardial mass by echocardiography and by magnetic resonance imaging. The diagnosis of cardiac endocardial tuberculoma was made, and she was treated with antituberculous therapy and an antiarrhythmic drug for one year. After a year, the mass was no longer present, and with all antiarrhythmic medications stopped, ventricular tachycardia could no longer be induced by electrophysiologic study. There has been no clinical recurrence.

Adult↗