530 Letters to the Editor to that after conventional balloon angioplasty. [4] Topol E. Caveats about elective coronary stenting. N Engl J Med 1994; 539^1. N. M. G. DEBBAS [5] Sigwart U, Puel J, Mirkowitch V, Joffre U. SIGWART F, Kappenberger I. Intravascular stents to prevent occlusion and restenosis E. EECKHOUT after transluminal angioplasty. N Engl P. VOGT J Med 1987; 316: 701-6. J. C. STAUFFER [6] Eeckhout E, Goy JJ, Stauffer JC, Vogt P, Kappenberger L. Endoluminal stentL. K.APPENBERGER ing of narrowed saphenous vein grafts: J. J. GOY long term clinical and angiographical Division of Cardiology, follow-up. Cathet Cardiovasc Diagn Centre Hospitalier Universitaire Vaudois, 1994; 32: 139-46. Lausanne, Switzerland References The mechanism of catecholaminergic polymorphic ventricular tachycardia may be triggered activity due to delayed afterdepolarization Bi-directional or polymorphic ventricular tachycardia (VT) is an uncommon disorder whose aetiology and mechanism is unknown. There are a few reports on patients with bidirectional or polymorphic VT in the absence of structural heart disease. Among them, Leenhardt et al. have reported cases of catecholaminergic polymorphic VT[1). Figure 1 (a) Twelve-lead electrocardiogram during bidirectional VT. There is an alternating pattern of right and left bundle branch block (R/LBBB), or an alternating left and right axis deviation with an RBBB or LBBB pattern. Thus, QRS pattern varied, (b) Recordings of MAP at right ventricular inflow. After bidirectional VT induced spontaneously by emotion disappeared, humps are observed during phase 4 (arrows) (c) During the infusion of isoproterenol, the humps gradually increased (arrows), (d) After the injection of propranolol, the humps gradually reduced and finally disappeared. Eur Heart J, Vol. 18, March 1997 Downloaded from http://eurheartj.oxfordjournals.org/ by guest on August 22, 2014 [1] Serruys PW, de Jaegere P, Kiemeneij F et al. A comparison of balloon expandable stent implantation with balloon angioplasty in patients with coronary artery disease. N Engl J Med 1994; 331: 489-95. [2] Fischman DL, Leon MB, Bairn DS et al. A randomized comparison of coronary stent placement and balloon angioplasty in the treatment of coronary artery disease. N Engl J Med 1994; 331: 496-501. [3] Kimura T, Nosaka H, Yokoi H, Iwabuchi M, Nobuyoshi M. Serial angiographic follow-up after PalmazSchatz stent implantation: comparison with conventional angioplasty. J Am Coll Cardiol 1993; 21: 1557-63. We also had a case of catecholaminergic polymorphic VT. A 14-year-old Japanese male was referred to us for the evaluation of ventricular tachyarrhythmias. Since the age of 5 years, he had experienced several episodes of syncope due to ventricular tachyarrhythmia associated with exercise or an increase in physical activity. His family history revealed no evidence of syncope or of sudden death. Physical examination revealed a slow pulse rate, and a cardiac pansystolic murmur (Levein 2/6) was audible at the apex of the heart. Results of biochemical tests were normal. The resting 12-lead ECG showed sinus bradycardia with a rate of 42 beats, min" 1 , a normal QT interval with QTc 0-41 s. Chest X-rays showed a cardiothoracic index of 0-48. Echocardiography revealed mild mitral valve regurgitation, but good ventricular function. Cardiac catheterization revealed normal coronary arteries. Despite the presence of mild mitral valve regurgitation, we were convinced that structural heart disease was absent. In this case, bidirectional or polymorphic VT was reproducibly induced by humoral (exercise, isoproterenol injection) or neurogenic (stress, emotion) sympathetic stimu- Letters to the Editor T. NAKAJIMA Y. KANEKO Y. TANIGUCHI K. HAYASHI* T. TAKIZAWA T. SUZUKIt R. NAGAI The Second Department of Internal Medicine, and *The Third Department of Internal Medicine, Cunma University School of Medicine, ^College of Medical Care and Technology, Gunma University, Maebashi 371, Japan and an end-systolic volume (ESV) of [1] Leenhardt A, Lucet V, Denjoy I et al. 160 ml at rest (heart rate (HR) 76/min, Catecholaminergic polymorphic ven- ejection fraction (EF) 45%). After extricular tachycardia in children; a ercise the EDV was 283 ml and the 7-year follow-up of 21 patients. Circu- ESV was 201ml (HR112/min, EF 29%). HELP LDL apheresis (B. lation 1995; 91: 1512-9. [2] Franz MR. Method and theory of Braun, Melsungen, Germany) was monophasic action potential recording performed every 2 weeks over a period (review). Prog Cardiovasc Disease of 6 months for a total of 12 treat1991; 33: 347-68. ments. The average cholesterol reduc[3] Bonatti V, Rolli A, Botti G. Recording tion after apheresis was 54%, LDLof monophasic action potentials of the cholesterol reduction was 61% and right ventricle in long QT syndromes complicated by severe ventricular fibrinogen reduction was 55%. After 6 arrhythmia. Eur Heart J 1983; 4: months, another exercise thallium-201 SPECT was performed. The images 168-79. [4] Shimizu W, Ohe T, Kurita T et al. Early acquired revealed the persistence of afterdepolarizations induced by iso- the area of necrosis but no marginal proterenol in patients with congenital ischaemia (Fig. 1 (B)). Radionuclide long QT syndrome. Circulation 1991; ventriculography showed a left ven84: 1915-23. tricular EDV of 264 ml and an ESV of 129 ml at rest (HR 80/min, EF51%). During exercise the EDV was 239 ml Improvement of myocardial perfusion and the ESV was 170 ml (HR 115/min, after low-density lipoprotein apheresis EF 29%). treatment We found an improvement Low-density lipoprotein (LDL) apher- in myocardial perfusion, as assessed esis (the selective extracorporeal re- by exercise thallium-201 SPECT, moval of LDL cholesterol from accompanied by an improvement plasma) is used to treat patients with in radionuclide ventriculography pardrug-refractory hypercholesterolaemia ameters after 6 months treatment with and coronary heart disease. There HELP LDL apheresis. Long-term are currently three LDL apheresis HELP LDL apheresis can induce remethods in clinical use'11: immuno- gression of coronary artery stenoses'21. adsorbtion with anti-apolipoprotein B However, numerous atherosclerosis antibodies, dextransulfate adsorption regression trials have revealed that the and heparin-induced extracorporeal clinical benefit derived from cholesLDL precipitation (HELP). We report terol lowering is greater than one the case of a patient who showed a would expect from the minimal notable improvement of myocardial changes observed by coronary angiogperfusion after 6 months of HELP raphy. This has prompted investigators to use other methods to evaluate LDL apheresis. 31 The patient, a 69-year-old the effects of cholesterol lowering' . Its influence on endothelial function woman, had suffered a postero-basal myocardial infarction at the age of 57. and myocardial perfusion needs to be Eight years later she underwent cor- studied. In two recently published onary bypass surgery in our hospital. studies, improvements in myocardial detected by thalliumAt that time we diagnosed familial perfusion were 41 hypercholesterolaemia and initiated 201 SPECT' and51 by positron emistreatment. Because her response to sion tomography' 3 and 6 months, diet and drug therapy was insufficient, respectively, after the cholesterolLDL apheresis was begun one year lowering intervention was started. The later. She was treated for 20 improvement observed in this patient months with immunoadsorbtion LDL is probably due to a reversal of apheresis (Baxter, Unterschleissheim, endothelial dysfunction, although, Germany) once every 2 weeks. There- because of the previous treatment with after the treatment method was immunoadsorbtion LDL apheresis, plaque regression also remains a switched to HELP LDL apheresis. possibility. The reduction of plasma Before the switch, exercise fibrinogen may also contribute to thallium-201 single-photon emission better perfusion of the myocardium computed tomography (SPECT) was by favourably influencing blood performed. The images obtained were rheology. consistent with an area of necrosis with marginal ischaemia. (Fig. 1(A)). This is, to our knowledge, the A technetium-99m radionuclide ven- first case of myocardial perfusion triculogram revealed a left ventricular improvement under LDL apheresis end-diastolic volume (EDV) of 290 ml documented by thallium-201 SPECT. References Eur Heart J, Vol. 18, March 1997 Downloaded from http://eurheartj.oxfordjournals.org/ by guest on August 22, 2014 lation. Twelve-lead ECG during bidirectional VT show various QRS complexes (Fig. 1 panel (a)). These ventricular tachyarrhythmias were halted by an injection of verapamil, 12 mg, or of propranolol, 2 mg, and were prevented by the administration of oral propranolol, 110 mg daily. Programmed electrical stimulation including triple extrastimuli of the right ventricle did not induce ventricular tachyarrhythmias. Monophasic action potential (MAP)'21 recording at the inflow of the right ventricle exhibited humps during phase 4 of the MAP (panel (b)). Similar humps were not recorded in other parts of the right ventricle. The humps gradually increased during the infusion of isoproterenol, 002mg. h ~ ' , and were followed by the occurrence of ventricular premature beats (panel (c)), then by the appearance of bidirectional VT. An injection of propranolol, 2 mg, led to a gradual reduction, and finally, a disappearance of the humps (panel (d)), accompanied by a disappearance of the bidirectional VT. From the MAP recordings and the effects of the drugs administered to this patient, it is conceivable that the humps observed during phase 4 of the MAP recordings may reflect delayed after depolarization (DAD) and bidirectional VT may be triggered by DAD-induced triggered activity. While DAD could be recorded only at the right ventricular inflow in this case, multiple separate foci may induce DAD. This fact is of interest, considering the difference between the idiopathic long QT syndrome and catecholaminergic polymorphic VT[I'3'41. This is the first case of catecholaminergic polymorphic VT where DAD could be recorded on MAP recordings. 531