Pacing-induced heart disease: Understanding the pathophysiology and improving outcomes

Expert Review of Cardiovascular Therapy

Volumn 9, Issue 7, 2011, Pages 877-886

  Elder, Douglas H J ^a   Lang, Chim C ^a   Choy, Anna Maria ^a  

^a UNIVERSITY OF DUNDEE   (United Kingdom)

Author keywords

biventricular pacemaker; endothelial dysfunction; heart failure; pacing site; right ventricular pacing; ventricular dyssynchrony

Indexed keywords

ANGIOTENSIN RECEPTOR ANTAGONIST; DIPEPTIDYL CARBOXYPEPTIDASE INHIBITOR;

ARTIFICIAL HEART PACEMAKER; ATRIOVENTRICULAR JUNCTION ARRHYTHMIA; BRADYCARDIA; CARDIAC RESYNCHRONIZATION THERAPY; CARDIOVASCULAR DISEASE; DIASTOLIC DYSFUNCTION; ENDOTHELIAL DYSFUNCTION; HEART ARRHYTHMIA; HEART DISEASE; HEART HEMODYNAMICS; HEART MUSCLE PERFUSION; HEART VENTRICLE PACING; HUMAN; NONHUMAN; PATHOPHYSIOLOGY; PRACTICE GUIDELINE; PROGNOSIS; RANDOMIZED CONTROLLED TRIAL (TOPIC); REVIEW; VENTRICULAR DYSSYNCHRONY;

ANIMALS; BRADYCARDIA; CARDIAC OUTPUT; CARDIAC PACING, ARTIFICIAL; HEART DISEASES; HEART VENTRICLES; HUMANS; PACEMAKER, ARTIFICIAL; VENTRICULAR DYSFUNCTION;

EID: 79961204308     PISSN: 14779072     EISSN: 17448344     Source Type: Journal    
DOI: 10.1586/erc.11.82     Document Type: Review

References (94)

1. Mcwilliams MJ. Electrical stimulation of the heart in man. BMJ 1(1), 348 (1889).
2. Wilkoff BL, Cook JR, Epstein AE et al. Dual-chamber pacing or ventricular backup pacing in patients with an implantable defibrillator: the Dual Chamber and VVI Implantable Defibrillator (DAVID) trial. JAMA 288(24), 3115-3123 (2002). (Pubitemid 36014128)
3. Sweeney MO, Hellkamp AS, Ellenbogen KA et al. Adverse effect of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker therapy for sinus node dysfunction. Circulation 107(23), 2932-2937 (2003). (Pubitemid 36736635)
4. Steinberg JS, Fischer A, Wang P et al. The clinical implications of cumulative right ventricular pacing in the multicenter automatic defibrillator trial II. J. Cardiovasc. Electrophysiol. 16(4), 359-365 (2005).
5. Sharma AD, Rizo-Patron C, Hallstrom AP et al. Percent right ventricular pacing predicts outcomes in the DAVID trial. Heart Rhythm 2(8), 830-834 (2005). (Pubitemid 41030726)
6. Shukla HH, Hellkamp AS, James EA et al. Heart failure hospitalization is more common in pacemaker patients with sinus node dysfunction and a prolonged paced QRS duration. Heart Rhythm 2(3), 245-251 (2005). (Pubitemid 40309819)
7. Elder D, Szwejkowski BR, Jain R et al. Younger age at time of pacemaker implantation is associated with worse survival. Circulation 122(21) (2010) (Meeting Abstracts).
8. Auricchio A, Stellbrink C, Sack S et al. Long-term clinical effect of hemodynamically optimized cardiac resynchronization therapy in patients with heart failure and ventricular conduction delay. J. Am. Coll. Cardiol. 39(12), 2026-2033 (2002). (Pubitemid 34628286)
9. Bristow MR, Saxon LA, Boehmer J et al. Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N. Engl. J. Med. 350(21), 2140-2150 (2004).
10. Healey JS, Toff WD, Lamas GA et al. Cardiovascular outcomes with atrial-based pacing compared with ventricular pacing: meta-analysis of randomized trials, using individual patient data. Circulation 114(1), 11-17 (2006). (Pubitemid 44305269)
11. Connolly SJ, Kerr CR, Gent M et al. Effects of physiologic pacing versus ventricular pacing on the risk of stroke and death due to cardiovascular causes. Canadian Trial of Physiologic Pacing Investigators. N. Engl. J. Med. 342(19), 1385-1391 (2000). (Pubitemid 30262395)
12. Kerr CR, Connolly SJ, Abdollah H et al. Canadian Trial of Physiological Pacing: effects of physiological pacing during long-term follow-up. Circulation 109(3), 357-362 (2004). (Pubitemid 38133904)
13. Lamas GA, Lee KL, Sweeney MO et al. Ventricular pacing or dual-chamber pacing for sinus-node dysfunction. N. Engl. J. Med. 346(24), 1854-1862 (2002). (Pubitemid 34603029)
14. Andersen HR, Nielsen JC, Thomsen PE et al. Long-term follow-up of patients from a randomised trial of atrial versus ventricular pacing for sick-sinus syndrome. Lancet 350(9086), 1210-1216 (1997). (Pubitemid 127445094)
15. Nielsen JC, Kristensen L, Andersen HR, Mortensen PT, Pedersen OL, Pedersen AK. A randomized comparison of atrial and dual-chamber pacing in 177 consecutive patients with sick sinus syndrome: echocardiographic and clinical outcome. J. Am. Coll. Cardiol. 42(4), 614-623 (2003). (Pubitemid 37000174)
16. Sweeney MO, Bank AJ, Nsah E et al. Minimizing ventricular pacing to reduce atrial fibrillation in sinus-node disease. N. Engl. J. Med. 357(10), 1000-1008 (2007). (Pubitemid 47367079)
17. Nielsen JC, Thomsen PE, Højberg S et al. A comparison of single-lead atrial pacing with dual-chamber pacing in sick sinus syndrome. Eur. Heart J. 32(6), 686-696 (2011).
18. Varma N. Left ventricular conduction delays induced by right ventricular apical pacing: effect of left ventricular dysfunction and bundle branch block. J. Cardiovasc. Electrophysiol. 19(2), 114-122 (2008). (Pubitemid 351197991)
19. Sagar S, Shen WK, Asirvatham SJ et al. Effect of long-term right ventricular pacing in young adults with structurally normal heart. Circulation 121(15), 1698-1705 (2010).
20. Cho GY, Kim HK, Kim YJ et al. Electrical and mechanical dyssynchrony for prediction of cardiac events in patients with systolic heart failure. Heart 96(13), 1029-1032 (2010).
21. Zhang Q, Fang F, Yip GW et al. Difference in prevalence and pattern of mechanical dyssynchrony in left bundle branch block occurring in right ventricular apical pacing versus systolic heart failure. Am. Heart J. 156(5), 989-995 (2008).
22. Auricchio A, Fantoni C, Regoli F et al. Characterization of left ventricular activation in patients with heart failure and left bundle-branch block. Circulation 109(9), 1133-1139 (2004). (Pubitemid 38332617)
23. Bax JJ, Bleeker GB, Marwick TH et al. Left ventricular dyssynchrony predicts response and prognosis after cardiac resynchronization therapy. J. Am. Coll. Cardiol. 44(9), 1834-1840 (2004). (Pubitemid 39424084)
24. Molhoek SG, Van Erven L, Bootsma M, Steendijk P, Van Der Wall EE, Schalij MJ. QRS duration and shortening to predict clinical response to cardiac resynchronization therapy in patients with end-stage heart failure. Pacing Clin. Electrophysiol. 27(3), 308-313 (2004). (Pubitemid 38352508)
25. Achilli A, Sassara M, Ficili S et al. Long-term effectiveness of cardiac resynchronization therapy in patients with refractory heart failure and 'narrow' QRS. J. Am. Coll. Cardiol. 42(12), 2117-2124 (2003). (Pubitemid 37549895)
26. Prinzen FW, Peschar M. Relation between the pacing induced sequence of activation and left ventricular pump function in animals. Pacing Clin. Electrophysiol. 25(4 Pt 1), 484-498 (2002). (Pubitemid 34438254)
27. Nahlawi M, Waligora M, Spies SM, Bonow RO, Kadish AH, Goldberger JJ. Left ventricular function during and after right ventricular pacing. J. Am. Coll. Cardiol. 44(9), 1883-1888 (2004). (Pubitemid 39424090)
28. Tantengco MV, Thomas RL, Karpawich PP. Left ventricular dysfunction after long-term right ventricular apical pacing in the young. J. Am. Coll. Cardiol. 37(8), 2093-2100 (2001). (Pubitemid 32548003)
29. Tops LF, Schalij MJ, Holman ER, Van Erven L, Van Der Wall EE, Bax JJ. Right ventricular pacing can induce ventricular dyssynchrony in patients with atrial fibrillation after atrioventricular node ablation. J. Am. Coll. Cardiol. 48(8), 1642-1648 (2006). (Pubitemid 44529710)
30. Mcdonald IG. Echocardiographic demonstration of abnormal motion of the interventricular septum in left bundle branch block. Circulation 48(2), 272-280 (1973).
31. Frais MA, Botvinick EH, Shosa DW et al. Phase image characterization of ventricular contraction in left and right bundle branch block. Am. J. Cardiol. 50(1), 95-105 (1982). (Pubitemid 12059371)
32. Bashore TM, Stine RA, Shaffer PB, Bush CA, Leier CV, Schaal SF. The noninvasive localization of ventricular pacing sites by radionuclide phase imaging. Circulation 70(4), 681-694 (1984). (Pubitemid 14020667)
33. Prinzen FW, Hunter WC, Wyman BT, Mcveigh ER. Mapping of regional myocardial strain and work during ventricular pacing: experimental study using magnetic resonance imaging tagging. J. Am. Coll. Cardiol. 33(6), 1735-1742 (1999).
34. Rosenqvist M, Isaaz K, Botvinick EH et al. Relative importance of activation sequence compared to atrioventricular synchrony in left ventricular function. Am. J. Cardiol. 67(2), 148-156 (1991).
35. Askenazi J, Alexander JH, Koenigsberg DI, Belic N, Lesch M. Alteration of left ventricular performance by left bundle branch block simulated with atrioventricular sequential pacing. Am. J. Cardiol. 53(1), 99-104 (1984). (Pubitemid 14217515)
36. Lieberman R, Padeletti L, Schreuder J et al. Ventricular pacing lead location alters systemic hemodynamics and left ventricular function in patients with and without reduced ejection fraction. J. Am. Coll. Cardiol. 48(8), 1634-1641 (2006). (Pubitemid 44528180)
37. Choy AM, Su HH, Elder DHJ et al. Right ventricular pacing impairs endothelial function in man. Europace 13(6), 853-858 (2011).
38. Lang CC, Karlin P, Haythe J, Lim TK, Mancini DM. Peak cardiac power output, measured noninvasively, is a powerful predictor of outcome in chronic heart failure. Circ. Heart Fail. 2(1), 33-38 (2009).
39. Van Oosterhout MF, Prinzen FW, Arts T et al. Asynchronous electrical activation induces asymmetrical hypertrophy of the left ventricular wall. Circulation 98(6), 588-595 (1998). (Pubitemid 28371258)
40. Vernooy K, Dijkman B, Cheriex EC, Prinzen FW, Crijns HJ. Ventricular remodeling during long-term right ventricular pacing following His bundle ablation. Am. J. Cardiol. 97(8), 1223-1227 (2006).
41. Barold SS, Ovsyshcher IE. Pacemaker-induced mitral regurgitation. Pacing Clin. 28(5), 357-360 (2005) (Pubitemid 40696293)
42. Thambo JB, Bordachar P, Garrigue S et al. Detrimental ventricular remodeling in patients with congenital complete heart block and chronic right ventricular apical pacing. Circulation 110(25), 3766-3772 (2004). (Pubitemid 40023974)
43. Karpawich PP, Rabah R, Haas JE. Altered cardiac histology following apical right ventricular pacing in patients with congenital atrioventricular block. Pacing Clin. Electrophysiol. 22(9), 1372-1377 (1999). (Pubitemid 29485038)
44. Tse HF, Lau CP. Long-term effect of right ventricular pacing on myocardial perfusion and function. J. Am. Coll. Cardiol. 29(4), 744-749 (1997).
45. Skalidis EI, Kochiadakis GE, Koukouraki SI et al. Myocardial perfusion in patients with permanent ventricular pacing and normal coronary arteries. J. Am. Coll. Cardiol. 37(1), 124-129 (2001). (Pubitemid 32051727)
46. Mcgowan RL, Welch TG, Zaret BL, Bryson AL, Martin ND, Flamm MD. Noninvasive myocardial imaging with potassium-43 and rubidium-81 in patients with left bundle branch block. Am. J. Cardiol. 38(4), 422-428 (1976).
47. Ono S, Nohara R, Kambara H, Okuda K, Kawai C. Regional myocardial perfusion and glucose metabolism in experimental left bundle branch block. Circulation 85(3), 1125-1131 (1992).
48. Prinzen FW, Augustijn CH, Arts T, Allessie MA, Reneman RS. Redistribution of myocardial fiber strain and blood flow by asynchronous activation. Am. J. Physiol. 259(2 Pt 2), H300-H308 (1990). (Pubitemid 20259403)
49. Baller D, Wolpers HG, Zipfel J, Bretschneider HJ, Hellige G. Comparison of the effects of right atrial, right ventricular apex and atrioventricular sequential pacing on myocardial oxygen consumption and cardiac efficiency: a laboratory investigation. Pacing Clin. Electrophysiol. 11(4), 394-403 (1988).
50. Sweeney MO, Prinzen FW. A new paradigm for physiologic ventricular pacing. J. Am. Coll. Cardiol. 47(2), 282-288 (2006). (Pubitemid 43063243)
51. Al-Hesayen A, Parker JD. Adverse effects of atrioventricular synchronous right ventricular pacing on left ventricular sympathetic activity, efficiency, and hemodynamic status. Am. J. Physiol. Heart Circ. Physiol. 291(5), H2377-H2379 (2006).
52. Hamdan MH, Zagrodzky JD, Joglar JA et al. Biventricular pacing decreases sympathetic activity compared with right ventricular pacing in patients with depressed ejection fraction. Circulation 102(9), 1027-1032 (2000). (Pubitemid 30656010)
53. Rubaj A, Ruciåski P, Rejdak K, et al. Biventricular versus right ventricular pacing decreases immune activation and augments nitric oxide production in patients with chronic heart failure. Eur. J. Heart Fail. 8(6), 615-620 (2006). (Pubitemid 44572961)
54. Akar JG, Al-Chekakie MO, Fugate T et al. Endothelial dysfunction in heart failure identifies responders to cardiac resynchronization therapy. Heart Rhythm 5(9), 1229-1235 (2008).
55. Al Chekakie MO, Gavigan T, Martin B et al. Abstract 3378: response to biventricular pacing is associated with improvement in endothelial function. Circulation 114(18 Meeting Abstracts) (2006).
56. Styliadis IH, Gouzoumas NI, Karvounis HI et al. Effects of variation of atrioventricular interval on left ventricular diastolic filling dynamics and atrial natriuretic peptide levels in patients with DDD pacing for complete heart block. Europace 7(6), 576-583 (2005). (Pubitemid 41488102)
57. Brunner M, Olschewski M, Geibel A, Bode C, Zehender M. Long-term survival after pacemaker implantation. Prognostic importance of gender and baseline patient characteristics. Eur. Heart J. 25(1), 88-95 (2004). (Pubitemid 38055597)
58. Thackray SD, Witte KK, Nikitin NP, Clark AL, Kaye GC, Cleland JG. The prevalence of heart failure and asymptomatic left ventricular systolic dysfunction in a typical regional pacemaker population. Eur. Heart J. 24(12), 1143-1152 (2003). (Pubitemid 36723580)
59. Kristensen L, Nielsen JC, Mortensen PT, Pedersen OL, Pedersen AK, Andersen HR. Incidence of atrial fibrillation and thromboembolism in a randomised trial of atrial versus dual chamber pacing in 177 patients with sick sinus syndrome. Heart 90(6), 661-666 (2004). (Pubitemid 38668543)
60. Anselme F. First clinical results of AAISAFER 2, a new mode to prevent ventricular pacing. Heart Rhythm 2(1 Suppl.), 4-99 (2005).
61. Savoure A, Fröhlig G, Galley D et al. A new dual-chamber pacing mode to minimize ventricular pacing. Pacing Clin. Electrophysiol. 28(Suppl. 1), S43-S46 (2005). (Pubitemid 40171079)
62. Gillis AM, Pürerfellner H, Israel CW et al. Reducing unnecessary right ventricular pacing with the managed ventricular pacing mode in patients with sinus node disease and AV block. Pacing Clin. Electrophysiol. 29(7), 697-705 (2006). (Pubitemid 44060736)
63. Deshmukh P, Casavant DA, Romanyshyn M, Anderson K. Permanent, direct His-bundle pacing: a novel approach to cardiac pacing in patients with normal His-Purkinje activation. Circulation 101(8), 869-877 (2000). (Pubitemid 30117882)
64. Deshmukh PM, Romanyshyn M. Direct His-bundle pacing: present and future. Pacing Clin. Electrophysiol. 27(6 Pt 2), 862-870 (2004). (Pubitemid 38748153)
65. Kronborg MB, Mortensen PT, Gerdes JC, Jensen HK, Nielsen JC. His and para-His pacing in AV block: feasibility and electrocardiographic findings. J. Interv. Card. Electrophysiol. DOI: 10.1007/ s10840-011-9565-1 (2011) (Epub ahead of print).
66. De Cock CC, Giudici MC, Twisk JW. Comparison of the haemodynamic effects of right ventricular outflow-tract pacing with right ventricular apex pacing: a quantitative review. Europace 5(3), 275-278 (2003). (Pubitemid 36934433)
67. Vanerio G, Vidal JL, Fernandez Banizi P, Banina Aguerre D, Viana P, Tejada J. Medium- and long-term survival after pacemaker implant: improved survival with right ventricular outflow tract pacing. J. Interv. Card. Electrophysiol. 21(3), 195-201 (2008).
68. Vlay SC. Right ventricular outflow tract pacing: practical and beneficial. A 9-year experience of 460 consecutive implants. Pacing Clin. Electrophysiol. 29(10), 1055-1062 (2006). (Pubitemid 44581392)
69. Medi C, Mond HG. Right ventricular outflow tract septal pacing: long-term follow-up of ventricular lead performance. Pacing Clin. Electrophysiol. 32(2), 172-176 (2009).
70. Burri H, Sunthorn H, Dorsaz PA, Viera I, Shah D. Thresholds and complications with right ventricular septal pacing compared to apical pacing. Pacing Clin. Electrophysiol. 30(Suppl. 1), S75-S78 (2007). (Pubitemid 46121814)
71. Kypta A, Steinwender C, Kammler J, Leisch F, Hofmann R. Long-term outcomes in patients with atrioventricular block undergoing septal ventricular lead implantation compared with standard apical pacing. Europace 10(5), 574-579 (2008). (Pubitemid 351775305)
72. Mcgavigan AD, Roberts-Thomson KC, Hillock RJ, Stevenson IH, Mond HG. Right ventricular outflow tract pacing: radiographic and electrocardiographic correlates of lead position. Pacing Clin. Electrophysiol. 29(10), 1063-1068 (2006). (Pubitemid 44581393)
73. Lane RE, Mayet J, Peters NS, Davies DW, Chow AW. Comparison of temporary bifocal right ventricular pacing and biventricular pacing for heart failure: evaluation by tissue Doppler imaging. Heart 94(1), 53-58 (2008).
74. Vardas PE, Auricchio A, Blanc JJ et al. Guidelines for cardiac pacing and cardiac resynchronization therapy. Eur. Heart J. 28(18), 2256-2295 (2007).
75. Elder D. Left ventricular dysfunction in patients referred for pacemakers - implications for pacemaker choice. Eur. J. Heart Fail. 7(Suppl.), 183-184 (2008).
76. Kindermann M, Hennen B, Jung J, Geisel J, Bohm M, Frohlig G. Biventricular versus conventional right ventricular stimulation for patients with standard pacing indication and left ventricular dysfunction: the Homburg Biventricular Pacing Evaluation (HOBIPACE).J. Am. Coll. Cardiol. 47(10), 1927-1937 (2006).
77. Vardas PE, Auricchio A, Blanc JJ et al. Guidelines for cardiac pacing and cardiac resynchronization therapy: the Task Force for Cardiac Pacing and Cardiac Resynchronization Therapy of the European Society of Cardiology. Developed in collaboration with the European Heart Rhythm Association. Eur. Heart J. 28(18), 2256-2295 (2007). (Pubitemid 47428944)
78. Yu CM, Chan JY, Zhang Q et al. Biventricular pacing in patients with bradycardia and normal ejection fraction. N. Engl. J. Med. 361(22), 2123-2134 (2009).
79. Miura T, Bhargava V, Guth BD et al. Increased afterload intensifies asynchronous wall motion and impairs ventricular relaxation. J. Appl. Physiol. 75(1), 389-396 (1993). (Pubitemid 23222001)
80. White JA, Yee R, Yuan X et al. Delayed enhancement magnetic resonance imaging predicts response to cardiac resynchronization therapy in patients with intraventricular dyssynchrony. J. Am. Coll. Cardiol. 48(10), 1953-1960 (2006). (Pubitemid 44738444)
81. Mitchell GF, Lamas GA, Vaughan DE, Pfeffer MA. Left ventricular remodeling in the year after first anterior myocardial infarction: a quantitative analysis of contractile segment lengths and ventricular shape. J. Am. Coll. Cardiol. 19(6), 1136-1144 (1992).
82. Brilla CG, Reams GP, Maisch B, Weber KT. Renin-angiotensin system and myocardial fibrosis in hypertension: regulation of the myocardial collagen matrix. Eur. Heart J. 14(Suppl. J), 57-61 (1993). (Pubitemid 23355392)
83. Kawai H, Stevens SY, Liang CS. Renin-angiotensin system inhibition on noradrenergic nerve terminal function in pacing-induced heart failure. Am. J. Physiol. Heart Circ. Physiol .279(6), H3012-H3019 (2000). (Pubitemid 32007067)
84. Hornig B, Arakawa N, Haussmann D, Drexler H. Differential effects of quinaprilat and enalaprilat on endothelial function of conduit arteries in patients with chronic heart failure. Circulation 98(25), 2842-2848 (1998). (Pubitemid 29003965)
85. Funabiki K, Onishi K, Dohi K et al. Combined angiotensin receptor blocker and ACE inhibitor on myocardial fibrosis and left ventricular stiffness in dogs with heart failure. Am. J. Physiol. Heart Circ. Physiol. 287(6), H2487-H2492 (2004). (Pubitemid 39561726)
86. Kurita T, Onishi K, Dohi K et al. Conventional therapy with an ACE inhibitor diminishes left ventricular dyssynchrony during the progression of heart failure. Int. J. Cardiol. 140(1), 48-54 (2010).
87. Williams SG, Connelly DT, Jackson M, Bennett A, Albouaini K, Todd DM. Does treatment with ACE inhibitors or angiotensin II receptor antagonists prevent atrial fibrillation after dual chamber pacemaker implantation? Europace 7(6), 554-559 (2005). (Pubitemid 41488099)
88. Curtis AB, Adamson PB, Chung E, Sutton MS, Tang F, Worley S. Biventricular versus right ventricular pacing in patients with AV block (BLOCK HF): clinical study design and rationale. J. Cardiovasc. Electrophysiol. 18(9), 965-971 (2007). (Pubitemid 47339054)
89. De Teresa E, Gómez-Doblas JJ, Lamas G et al. Preventing ventricular dysfunction in pacemaker patients without advanced heart failure: rationale and design of the PREVENT-HF study. Europace 9(6), 442-446 (2007). (Pubitemid 47261094)
90. Funck RC, Blanc JJ, Mueller HH, Schade-Brittinger C, Bailleul C, Maisch B. Biventricular stimulation to prevent cardiac desynchronization: rationale, design, and endpoints of the 'Biventricular Pacing for Atrioventricular Block to Prevent Cardiac Desynchronization (BioPace)' study. Europace 8(8), 629-635 (2006). (Pubitemid 44295761)
91. Spickler JW, Rasor NS, Kezdi P, Misra SN, Robins KE, Leboeuf C. Totally self-contained intracardiac pacemaker. J. Electrocardiol. 3(3-4), 325-331 (1970).
92. Lee KL, Lau CP, Tse HF et al. First human demonstration of cardiac stimulation with transcutaneous ultrasound energy delivery: implications for wireless pacing with implantable devices. J. Am. Coll. Cardiol. 50(9), 877-883 (2007). (Pubitemid 47268744)
93. Lamas GA, Orav EJ, Stambler BS et al. Quality of life and clinical outcomes in elderly patients treated with ventricular pacing as compared with dual-chamber pacing. N. Engl. J. Med. 338, 1097-1104 (1998). (Pubitemid 28227479)
94. Toff WD, Camm AJ, Skehan JD et al. Single-chamber versus dual-chamber pacing for high-grade atrioventricular block. N. Engl. J. Med. 353, 145-155 (2005). (Pubitemid 41058346)