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Successful catheter ablation of persistent electrical storm late post myocardial infarction by targeting purkinje arborization triggers.

Thoppil PS, Rao BH, Jaishankar S, Narasimhan C - Indian Pacing Electrophysiol J (2008)

Bottom Line: Drug refractory ventricular tachycardia (VT) occurring as a storm after acute myocardial infarction has grave prognosis.We report a case of a middle-aged lady who presented with drug refractory VT that lead to persistent electrical storm two weeks after an anterior wall myocardial infarction.She underwent a successful catheter ablation of VT followed a few days later by implantation of an AICD.

View Article: PubMed Central - PubMed

Affiliation: Division of Electrophysiology, Department of Cardiology, CARE Hospitals and CARE Foundation, Hyderabad, India.

ABSTRACT
Drug refractory ventricular tachycardia (VT) occurring as a storm after acute myocardial infarction has grave prognosis. We report a case of a middle-aged lady who presented with drug refractory VT that lead to persistent electrical storm two weeks after an anterior wall myocardial infarction. She underwent a successful catheter ablation of VT followed a few days later by implantation of an AICD. Catheter ablation of the VT could control the persistent electrical storm and the patient was free from a recurrence of VT at three month follow up.

No MeSH data available.


Related in: MedlinePlus

Surface ECG and intracardiac tracings during substrate mapping showing late diastolic potentials (Bold Arrows) in MapD catheter.
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Figure 2: Surface ECG and intracardiac tracings during substrate mapping showing late diastolic potentials (Bold Arrows) in MapD catheter.

Mentions: She underwent an emergency electrophysiology study during which many attempts at cardioversion and overdrive pacing failed to control the storm. Access to the left ventricle was achieved retrogradely across the aortic valve. LV mapping was performed using a non-fluoroscopic electroanatomic system (CARTO, Biosense Webster Inc, USA) and 7.5F Navistar F curve irrigated tip catheter. A bipolar LV voltage map was created to define the scar and border zone of MI. The infarct area was defined during sinus rhythm by electrograms with an amplitude ≤ 1.5 mV; dense scars were defined by electrograms with an amplitude ≤ 0.5 mV. Once the map was completed, amplitude scale was adjusted (0.2 to 0.5 mV), setting the value for scar at ≤ 0.2 mV to identify conducting channels within the scar area. They were marked out as corridors of continuous electrograms differentiated from the surrounding scar tissue by a higher amplitude, bounded by two scar areas, or by one scar area and the mitral annulus, and connected to normal myocardium by at least two sites [3]. A large scar at anterolateral wall and apex of LV was mapped and the infarct area was completely encircled. RF lesions were delivered using an irrigated tip catheter at 30 W power, 43ºC temperature with an irrigation rate of 20 to 30 mL/min. Whenever a conducting channel was identified along the border zone of scar, a RF lesion was immediately applied to transect the conducting channel. Following the initial ablation of conducting channels and of sites of LV tagged by late diastolic potentials (Figure 2), the VT storm terminated temporarily but the monomorphic VT could still be reinduced on programmed ventricular stimulation during isoprenaline infusion. Pace mapping at various endocardial LV sites did not produce an ideal match of clinical VT and hence that course was not pursued further. A further substrate mapping of LV revealed a discrete Purkinje potential preceding spontaneous ventricular ectopic beat (which was not evident in sinus beats ), suggesting a driver role in the sustenance of the tachycardia (Figure 3). RF lesions were delivered at the LV sites where Purkinje potential preceded the ventricular activation by ≥ 30 ms during ventricular ectopic beats and during tachycardia (Figure 4). After this targeted ablation of Purkinje potential triggers, VT became noninducible with aggressive programmed ventricular stimulation during isoprenaline infusion. A single chamber ICD was implanted a week later and she was discharged in a stable condition. No recurrence of VT or ICD shocks occurred in the two month follow-up.


Successful catheter ablation of persistent electrical storm late post myocardial infarction by targeting purkinje arborization triggers.

Thoppil PS, Rao BH, Jaishankar S, Narasimhan C - Indian Pacing Electrophysiol J (2008)

Surface ECG and intracardiac tracings during substrate mapping showing late diastolic potentials (Bold Arrows) in MapD catheter.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2572020&req=5

Figure 2: Surface ECG and intracardiac tracings during substrate mapping showing late diastolic potentials (Bold Arrows) in MapD catheter.
Mentions: She underwent an emergency electrophysiology study during which many attempts at cardioversion and overdrive pacing failed to control the storm. Access to the left ventricle was achieved retrogradely across the aortic valve. LV mapping was performed using a non-fluoroscopic electroanatomic system (CARTO, Biosense Webster Inc, USA) and 7.5F Navistar F curve irrigated tip catheter. A bipolar LV voltage map was created to define the scar and border zone of MI. The infarct area was defined during sinus rhythm by electrograms with an amplitude ≤ 1.5 mV; dense scars were defined by electrograms with an amplitude ≤ 0.5 mV. Once the map was completed, amplitude scale was adjusted (0.2 to 0.5 mV), setting the value for scar at ≤ 0.2 mV to identify conducting channels within the scar area. They were marked out as corridors of continuous electrograms differentiated from the surrounding scar tissue by a higher amplitude, bounded by two scar areas, or by one scar area and the mitral annulus, and connected to normal myocardium by at least two sites [3]. A large scar at anterolateral wall and apex of LV was mapped and the infarct area was completely encircled. RF lesions were delivered using an irrigated tip catheter at 30 W power, 43ºC temperature with an irrigation rate of 20 to 30 mL/min. Whenever a conducting channel was identified along the border zone of scar, a RF lesion was immediately applied to transect the conducting channel. Following the initial ablation of conducting channels and of sites of LV tagged by late diastolic potentials (Figure 2), the VT storm terminated temporarily but the monomorphic VT could still be reinduced on programmed ventricular stimulation during isoprenaline infusion. Pace mapping at various endocardial LV sites did not produce an ideal match of clinical VT and hence that course was not pursued further. A further substrate mapping of LV revealed a discrete Purkinje potential preceding spontaneous ventricular ectopic beat (which was not evident in sinus beats ), suggesting a driver role in the sustenance of the tachycardia (Figure 3). RF lesions were delivered at the LV sites where Purkinje potential preceded the ventricular activation by ≥ 30 ms during ventricular ectopic beats and during tachycardia (Figure 4). After this targeted ablation of Purkinje potential triggers, VT became noninducible with aggressive programmed ventricular stimulation during isoprenaline infusion. A single chamber ICD was implanted a week later and she was discharged in a stable condition. No recurrence of VT or ICD shocks occurred in the two month follow-up.

Bottom Line: Drug refractory ventricular tachycardia (VT) occurring as a storm after acute myocardial infarction has grave prognosis.We report a case of a middle-aged lady who presented with drug refractory VT that lead to persistent electrical storm two weeks after an anterior wall myocardial infarction.She underwent a successful catheter ablation of VT followed a few days later by implantation of an AICD.

View Article: PubMed Central - PubMed

Affiliation: Division of Electrophysiology, Department of Cardiology, CARE Hospitals and CARE Foundation, Hyderabad, India.

ABSTRACT
Drug refractory ventricular tachycardia (VT) occurring as a storm after acute myocardial infarction has grave prognosis. We report a case of a middle-aged lady who presented with drug refractory VT that lead to persistent electrical storm two weeks after an anterior wall myocardial infarction. She underwent a successful catheter ablation of VT followed a few days later by implantation of an AICD. Catheter ablation of the VT could control the persistent electrical storm and the patient was free from a recurrence of VT at three month follow up.

No MeSH data available.


Related in: MedlinePlus