- Email: [email protected]
Refractory Heart Failure After Failed Subcutaneous Implantable Cardioverter-Defibrillator Defibrillation Testing: The Potential Value of Early Mechanical Circulatory Support
Author’s Accepted Manuscript Refractory Heart Failure after Failed Subcutaneous Implantable Cardioverter-Defibrillator Defibrillation Testing: The Potential Value of Early Mechanical Circulatory Support McNamara Connor, Emile G. Daoud, Leonid Gorelik, Angela Sipes, Jaret D. Tyler, Michael Essandoh
PII: DOI: Reference:
www.elsevier.com/locate/buildenv
S1053-0770(17)30517-7 http://dx.doi.org/10.1053/j.jvca.2017.05.039 YJCAN4175
To appear in: Journal of Cardiothoracic and Vascular Anesthesia Cite this article as: McNamara Connor, Emile G. Daoud, Leonid Gorelik, Angela Sipes, Jaret D. Tyler and Michael Essandoh, Refractory Heart Failure after Failed Subcutaneous Implantable Cardioverter-Defibrillator Defibrillation Testing: The Potential Value of Early Mechanical Circulatory Support, Journal of Cardiothoracic and Vascular Anesthesia, http://dx.doi.org/10.1053/j.jvca.2017.05.039 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Refractory Heart Failure after failed Subcutaneous Implantable Cardioverter-Defibrillator Defibrillation Testing: The Potential Value of Early Mechanical Circulatory Support.
McNamara Connor, MD1, Emile G. Daoud, MD2, Leonid Gorelik, MD1, Angela Sipes, BS1, Jaret D Tyler, MD2, Michael Essandoh, MD1*
1
Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus,
OH, USA. 2
Department of Internal Medicine, Division of Cardiovascular Medicine,
Wexner Medical Center, The Ohio State University, Columbus, OH, USA.
Corresponding Author: *
Michael Essandoh, M.D.
Department of Anesthesiology Division of Cardiothoracic and Vascular Anesthesiology The Ohio StateUniversity, Wexner Medical Center Doan Hall N 411, 410 W 10th Ave., Columbus, OH. 43210. Tel: (614)293-8487 Fax: (614)293-8153 Email: [email protected]
1
Introduction
The subcutaneous implantable cardioverter-defibrillator (S-ICD) system (Boston Scientific, Marlborough, MA, USA) has gained popularity for the treatment of life-threatening ventricular arrhythmias in patients who do not require bradycardia or antitachycardia pacing.1-7 The S-ICD system (subcutaneously implanted single shock electrode and pulse generator) is implanted extrathoracically in the left chest wall and avoids direct contact with the cardiovascular system.1,2,4,5,7 At the time of implantation, defibrillation testing (DT) is considered important to assess successful shock conversion by the S-ICD system of induced ventricular fibrillation (VF).1,2,4,5,7,8 Considering that malpositioning of the electrode and/or the pulse generator may impair optimal treatment of ventricular tachycardia (VT) or VF in the ambulatory setting, DT testing at the time of implantation may help reduce sudden cardiac death with S-ICD treatment. Defibrillation testing with the S-ICD, however, may cause cardiovascular collapse, akin to transvenous ICD therapy.8,11,12
The authors present a case of refractory VF and prolonged cardiogenic shock refractory to inotropic support that occurred during S-ICD DT in a patient with idiopathic dilated cardiomyopathy. The usefulness of short-term mechanical circulatory support for the management of this complication is further discussed.
2
Case Report A 39-year-old male with idiopathic dilated cardiomyopathy and hypertension presented for SICD implantation for primary prevention of sudden cardiac death. A preoperative echocardiogram showed a severely dilated left ventricle (left ventricular end diastolic dimension of 6.4 cm) with an ejection fraction of 20%, a mildly dilated right ventricle with mild systolic dysfunction, and moderate mitral regurgitation. Additionally, cardiac magnetic resonance imaging demonstrated global left ventricular fibrosis, severe left ventricular enlargement (left ventricular end-diastolic volume index of 178 ml/m2) and severe left ventricular systolic dysfunction.
The patient was taken to the electrophysiology laboratory procedure room for S-ICD implantation under general anesthesia (GA). A right radial arterial catheter was inserted for hemodynamic monitoring. Induction of GA and intubation were then performed without incident. The initial vital signs after induction were a mean arterial blood pressure of 82 mmHg and a heart rate of 77 bpm. The S-ICD was implanted in standard fashion.1,7 The patient was hemodynamically stable during implantation of the S-ICD system, with a mean arterial pressure > 70 mmHg, and did not require inotrope or vasopressor support. After completion of S-ICD system insertion, DT testing was performed.8 Ventricular fibrillation was induced using a 50-Hz burst pacing from the S-ICD. The S-ICD appropriately sensed and detected the VF and delivered 65J shock energy after approximately 15 seconds of VF. This shock however failed to convert VF to sinus rhythm. External biphasic shock energy of 360J was subsequently delivered without success, followed by two consecutive S-ICD shocks of 80J, which were also unsuccessful.
3
Cardiopulmonary resuscitation using the adult cardiac arrest algorithm was initiated and after the sixth external 360J shock, the patient converted to sinus rhythm. The total duration from the induction of VF to final restoration of sinus rhythm was 180 seconds. After the return of spontaneous circulation, the patient was severely hypotensive and required epinephrine and norepinephrine infusions for circulatory support. However, despite escalating doses of inotropic and vasopressor support and sinus rhythm, the mean arterial pressure remained quite low, < 45 mmHg, consistent with acute cardiogenic shock. A transthoracic echocardiogram was performed and demonstrated a stunned left ventricle with an estimated ejection fraction of 10% despite the treatment strategy above. The decision was made to provide mechanical support for the failing left ventricle. Interventional cardiology was emergently consulted and an intra-aortic balloon pump was inserted, which resulted in significant hemodynamic improvement (mean arterial pressure > 65 mmHg). Since subcutaneous defibrillation was unsuccessful, the S-ICD system was extracted. The patient was extubated 6 hours later and the cardiogenic shock resolved rapidly. The inotropes and intra-aortic balloon pump were discontinued 18 hours later. The patient was discharged 2 days post procedure without change in mental or functional status, and no change in medical therapy, after refusing implantation of a transvenous ICD system.
Discussion The S-ICD provides shock therapy with a subcutaneous electrode and avoids complications associated with transvenous ICD systems such as pneumothorax, infections, vascular occlusions, endocarditis, cardiac perforation, and tricuspid valve injury.1-7,14 The vast majority of S-ICD implantations are uncomplicated, but this case report highlights that certain patients may have hemodynamic compromise during DT.
4
The consensus among electrophysiology experts is to perform DT at the time of S-ICD implantation to ensure appropriate termination of VF in a controlled setting.8,13,15 This consensus is supported by the Heart Rhythm Society and the European Heart Rhythm Association due to the absence of data supporting the safety and efficacy of DT avoidance with the S-ICD.15 Although DT testing is ideal, it may cause cardiovascular failure in certain patients.12,15 Experience with transvenous ICD systems have identified conditions that are associated with complications with DT including, but not limited to, idiopathic cardiomyopathy, left ventricular dilatation, severe left ventricular systolic dysfunction, poor lead position, electrolyte imbalance, and antiarrhythmic drug therapy.8-12 Also,
even when indicated, repeated shock therapy
exacerbates hemodynamics reducing the likelihood of successful VF conversion; hence, prompt conversion of VF for any patient in any scenario is crucial.15
The patient presented in this case had many of the risk factors associated with elevated DT including increased left ventricular end diastolic dimension (6.4 cm), severely depressed left ventricular ejection fraction, idiopathic cardiomyopathy, and a downward hemodynamic spiral with each unsuccessful shock conversion and greater time spent in VF. The high number of shocks coupled with the prolonged duration of VF led to acute severe myocardial stunning refractory to inotropic support. Prompt recognition of poor response to inotropic support despite restoration of sinus rhythm is important and aggressive mechanical circulatory support, in this case intra-aortic balloon counterpulsation, should be considered to rescue the patient. While other mechanical circulatory support options such as veno-arterial extracorporeal membrane oxygenation and percutaneous left ventricular assist devices provide adequate support to the
5
failing left ventricle, they are more invasive and were not considered in our case. The prompt reversibility of the hemodynamics with the balloon pump and restoration of baseline cardiac performance support the concept that the primary insult was the combination of prolonged duration of VF and the multiple shocks, rather than other etiologies.15 Because of rapid response, the patient did not develop any neurologic or thromboembolic sequela.
Although quite unlikely, this case report highlights the need for having the proper staff and equipment readily available for an S-ICD procedure to manage a patient that is not easily rescued following VF induction.
Conclusions The risk-benefit ratio of S-ICD DT is debatable; however, the absence of data regarding clinical shock therapy efficacy in the setting of deferred S-ICD DT, coupled with the extrathoracic location of the S-ICD system (potential for high DTs and need for system revision), may warrant the performance of DT testing during S-ICD implantation. Defibrillation testing of the S-ICD, however, may cause acute hemodynamic compromise, stroke, thromboembolism, and death in high-risk patients. It is imperative to identify patients at risk for post-DT heart failure and plan appropriately. Mechanical circulatory support may be useful and warrants consideration in patients with refractory cardiogenic shock. Long-term experience with the S-ICD will help determine the absolute need for DT testing during S-ICD implantation. In the interim, anesthesiologists should be aware of the potential for defibrillator shock energy-induced systolic and diastolic heart failure during S-ICD DT.
6
References 1. Essandoh, M.K., Otey AJ, Abdel-Rasoul M, Eet al: Monitored Anesthesia Care for Subcutaneous Cardioverter-Defibrillator Implantation: A Single-Center Experience. J Cardiothorac Vasc Anesth, 2016. 30(5): p. 1228-33. 2. Saxon LA: The Subcutaneous Implantable Defibrillator: A New Technology That Raises an Existential Question for the Implantable Cardioverter-Defibrillator. Circulation 2013; 128(9) 938-940. 3. Majithia A, Estes NA, Weinstock J: Advances in Sudden Death Prevention: The Emerging Role of a Fully Subcutaneous Defibrillator. JAMA 2014; 127(3) 188-194. 4. Burke MC, Gold MR, Knight BP, Barr CS, Theuns DA, Boersma LV, Knops RE, Weiss R, Leon AR, Herre JM, Husby M, Stein KM, Lambiase PD: Safety and Efficacy of the Totally Subcutaneous Implantable Defibrillator: 2-Year Results From a Pooled Analysis of the IDE Study and EFFORTLESS Registry. J Am Coll Cardiol 2015; 65(16):1605-15. 5. Weiss R, Knight BP, Gold MR, Leon AR, Herre JM, Hood M, Rashtian M, Burke MC: Safety and efficacy of a totally subcutaneous implantable-cardioverter defibrillator. Circulation 2013; 128(9) 944-953. 6. Lambiase PD, Barr C, Theuns DA, Knops R, Neuzil P, Johansen JB, Hood M, Pedersen S, Kääb S, Murgatroyd F, Reeve HL, Carter N, Boersma L, EFFORTLESS Investigators: Worldwide experience with a totally subcutaneous implantable defibrillator: early results from the EFFORTLESS S-ICD Registry. Eur Heart J 2014; 35(25):1657-65.
7
7. Essandoh MK, Portillo JG, Weiss R, Otey AJ, Zuleta-Alarcon AN, Humeidan ML, Torres JL, Flores AS, Castellon-Larios K, Abdel-Rasoul M, Andritsos MJ, Perez WJ, Stein EJ, Turner KR, Dimitrova GT, Awad H, Bhandary SP, Tripathi RS, Josepha NC, Hummel JD, Augostini RS, Kalbfleisch SJ, Tyler JD, Houmsse M, Daoud EG: Anesthesia care for subcutaneous implantable cardioverter/defibrillator placement: a single-center experience. J Clin Anesth 2016; 31:53–59. 8. Wilkoff BL, Fauchier L, Stiles MK, et al: 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement of optimal implantable cardioverter-defibrillator programming and testing. Heart Rhythm 2016; 13(2): e50-86. 9. Curtis AB: Defibrillation threshold testing in implantable cardioverter-defibrillators: Might less be more than enough? J Am Coll Cardiol 2008; 52(7):557-8. 10. Kutyifa V, Moss AJ: Defibrillation testing is not required during routine ICD implantation. Eur Heart J 2015; 36(25):2508-9. 11. Toh N, Nishii N, Nakamura K, et al: Cardiac dysfunction and prolonged hemodynamic deterioration after implantable cardioverter-defibrillator shock in patients with systolic heart failure. Circ Arrhythm Electrophysiol 2012; 5:898-905. 12. Birnie D, Tung S, Simpson C, et al: Complications associated with defibrillation threshold testing: The Canadian experience. Heart Rhythm 2008; 5(3): 387-390. 13. Frommeyer G, Zumhagen S, Dechering DG, et al: Intraoperative defibrillation testing of subcutaneous implantable cardioverter-defibrillator systems-A simple issue? J Am Heart Assoc 2016; 5(3): e003181
8
14. Friedman DJ, Parzynski CS, Varosy PD, et al: Trends and in-hospital outcomes associated with adoption of the subcutaneous implantable cardioverter defibrillator in the United States. JAMA Cardiol 2016; 1(8):900-911. 15. Wilkoff BL, Fauchier L, Stiles MK, et al: 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing. J. Arrhythm 2016; 32(1):1-28.
9
PII: DOI: Reference:
www.elsevier.com/locate/buildenv
S1053-0770(17)30517-7 http://dx.doi.org/10.1053/j.jvca.2017.05.039 YJCAN4175
To appear in: Journal of Cardiothoracic and Vascular Anesthesia Cite this article as: McNamara Connor, Emile G. Daoud, Leonid Gorelik, Angela Sipes, Jaret D. Tyler and Michael Essandoh, Refractory Heart Failure after Failed Subcutaneous Implantable Cardioverter-Defibrillator Defibrillation Testing: The Potential Value of Early Mechanical Circulatory Support, Journal of Cardiothoracic and Vascular Anesthesia, http://dx.doi.org/10.1053/j.jvca.2017.05.039 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Refractory Heart Failure after failed Subcutaneous Implantable Cardioverter-Defibrillator Defibrillation Testing: The Potential Value of Early Mechanical Circulatory Support.
McNamara Connor, MD1, Emile G. Daoud, MD2, Leonid Gorelik, MD1, Angela Sipes, BS1, Jaret D Tyler, MD2, Michael Essandoh, MD1*
1
Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus,
OH, USA. 2
Department of Internal Medicine, Division of Cardiovascular Medicine,
Wexner Medical Center, The Ohio State University, Columbus, OH, USA.
Corresponding Author: *
Michael Essandoh, M.D.
Department of Anesthesiology Division of Cardiothoracic and Vascular Anesthesiology The Ohio StateUniversity, Wexner Medical Center Doan Hall N 411, 410 W 10th Ave., Columbus, OH. 43210. Tel: (614)293-8487 Fax: (614)293-8153 Email: [email protected]
1
Introduction
The subcutaneous implantable cardioverter-defibrillator (S-ICD) system (Boston Scientific, Marlborough, MA, USA) has gained popularity for the treatment of life-threatening ventricular arrhythmias in patients who do not require bradycardia or antitachycardia pacing.1-7 The S-ICD system (subcutaneously implanted single shock electrode and pulse generator) is implanted extrathoracically in the left chest wall and avoids direct contact with the cardiovascular system.1,2,4,5,7 At the time of implantation, defibrillation testing (DT) is considered important to assess successful shock conversion by the S-ICD system of induced ventricular fibrillation (VF).1,2,4,5,7,8 Considering that malpositioning of the electrode and/or the pulse generator may impair optimal treatment of ventricular tachycardia (VT) or VF in the ambulatory setting, DT testing at the time of implantation may help reduce sudden cardiac death with S-ICD treatment. Defibrillation testing with the S-ICD, however, may cause cardiovascular collapse, akin to transvenous ICD therapy.8,11,12
The authors present a case of refractory VF and prolonged cardiogenic shock refractory to inotropic support that occurred during S-ICD DT in a patient with idiopathic dilated cardiomyopathy. The usefulness of short-term mechanical circulatory support for the management of this complication is further discussed.
2
Case Report A 39-year-old male with idiopathic dilated cardiomyopathy and hypertension presented for SICD implantation for primary prevention of sudden cardiac death. A preoperative echocardiogram showed a severely dilated left ventricle (left ventricular end diastolic dimension of 6.4 cm) with an ejection fraction of 20%, a mildly dilated right ventricle with mild systolic dysfunction, and moderate mitral regurgitation. Additionally, cardiac magnetic resonance imaging demonstrated global left ventricular fibrosis, severe left ventricular enlargement (left ventricular end-diastolic volume index of 178 ml/m2) and severe left ventricular systolic dysfunction.
The patient was taken to the electrophysiology laboratory procedure room for S-ICD implantation under general anesthesia (GA). A right radial arterial catheter was inserted for hemodynamic monitoring. Induction of GA and intubation were then performed without incident. The initial vital signs after induction were a mean arterial blood pressure of 82 mmHg and a heart rate of 77 bpm. The S-ICD was implanted in standard fashion.1,7 The patient was hemodynamically stable during implantation of the S-ICD system, with a mean arterial pressure > 70 mmHg, and did not require inotrope or vasopressor support. After completion of S-ICD system insertion, DT testing was performed.8 Ventricular fibrillation was induced using a 50-Hz burst pacing from the S-ICD. The S-ICD appropriately sensed and detected the VF and delivered 65J shock energy after approximately 15 seconds of VF. This shock however failed to convert VF to sinus rhythm. External biphasic shock energy of 360J was subsequently delivered without success, followed by two consecutive S-ICD shocks of 80J, which were also unsuccessful.
3
Cardiopulmonary resuscitation using the adult cardiac arrest algorithm was initiated and after the sixth external 360J shock, the patient converted to sinus rhythm. The total duration from the induction of VF to final restoration of sinus rhythm was 180 seconds. After the return of spontaneous circulation, the patient was severely hypotensive and required epinephrine and norepinephrine infusions for circulatory support. However, despite escalating doses of inotropic and vasopressor support and sinus rhythm, the mean arterial pressure remained quite low, < 45 mmHg, consistent with acute cardiogenic shock. A transthoracic echocardiogram was performed and demonstrated a stunned left ventricle with an estimated ejection fraction of 10% despite the treatment strategy above. The decision was made to provide mechanical support for the failing left ventricle. Interventional cardiology was emergently consulted and an intra-aortic balloon pump was inserted, which resulted in significant hemodynamic improvement (mean arterial pressure > 65 mmHg). Since subcutaneous defibrillation was unsuccessful, the S-ICD system was extracted. The patient was extubated 6 hours later and the cardiogenic shock resolved rapidly. The inotropes and intra-aortic balloon pump were discontinued 18 hours later. The patient was discharged 2 days post procedure without change in mental or functional status, and no change in medical therapy, after refusing implantation of a transvenous ICD system.
Discussion The S-ICD provides shock therapy with a subcutaneous electrode and avoids complications associated with transvenous ICD systems such as pneumothorax, infections, vascular occlusions, endocarditis, cardiac perforation, and tricuspid valve injury.1-7,14 The vast majority of S-ICD implantations are uncomplicated, but this case report highlights that certain patients may have hemodynamic compromise during DT.
4
The consensus among electrophysiology experts is to perform DT at the time of S-ICD implantation to ensure appropriate termination of VF in a controlled setting.8,13,15 This consensus is supported by the Heart Rhythm Society and the European Heart Rhythm Association due to the absence of data supporting the safety and efficacy of DT avoidance with the S-ICD.15 Although DT testing is ideal, it may cause cardiovascular failure in certain patients.12,15 Experience with transvenous ICD systems have identified conditions that are associated with complications with DT including, but not limited to, idiopathic cardiomyopathy, left ventricular dilatation, severe left ventricular systolic dysfunction, poor lead position, electrolyte imbalance, and antiarrhythmic drug therapy.8-12 Also,
even when indicated, repeated shock therapy
exacerbates hemodynamics reducing the likelihood of successful VF conversion; hence, prompt conversion of VF for any patient in any scenario is crucial.15
The patient presented in this case had many of the risk factors associated with elevated DT including increased left ventricular end diastolic dimension (6.4 cm), severely depressed left ventricular ejection fraction, idiopathic cardiomyopathy, and a downward hemodynamic spiral with each unsuccessful shock conversion and greater time spent in VF. The high number of shocks coupled with the prolonged duration of VF led to acute severe myocardial stunning refractory to inotropic support. Prompt recognition of poor response to inotropic support despite restoration of sinus rhythm is important and aggressive mechanical circulatory support, in this case intra-aortic balloon counterpulsation, should be considered to rescue the patient. While other mechanical circulatory support options such as veno-arterial extracorporeal membrane oxygenation and percutaneous left ventricular assist devices provide adequate support to the
5
failing left ventricle, they are more invasive and were not considered in our case. The prompt reversibility of the hemodynamics with the balloon pump and restoration of baseline cardiac performance support the concept that the primary insult was the combination of prolonged duration of VF and the multiple shocks, rather than other etiologies.15 Because of rapid response, the patient did not develop any neurologic or thromboembolic sequela.
Although quite unlikely, this case report highlights the need for having the proper staff and equipment readily available for an S-ICD procedure to manage a patient that is not easily rescued following VF induction.
Conclusions The risk-benefit ratio of S-ICD DT is debatable; however, the absence of data regarding clinical shock therapy efficacy in the setting of deferred S-ICD DT, coupled with the extrathoracic location of the S-ICD system (potential for high DTs and need for system revision), may warrant the performance of DT testing during S-ICD implantation. Defibrillation testing of the S-ICD, however, may cause acute hemodynamic compromise, stroke, thromboembolism, and death in high-risk patients. It is imperative to identify patients at risk for post-DT heart failure and plan appropriately. Mechanical circulatory support may be useful and warrants consideration in patients with refractory cardiogenic shock. Long-term experience with the S-ICD will help determine the absolute need for DT testing during S-ICD implantation. In the interim, anesthesiologists should be aware of the potential for defibrillator shock energy-induced systolic and diastolic heart failure during S-ICD DT.
6
References 1. Essandoh, M.K., Otey AJ, Abdel-Rasoul M, Eet al: Monitored Anesthesia Care for Subcutaneous Cardioverter-Defibrillator Implantation: A Single-Center Experience. J Cardiothorac Vasc Anesth, 2016. 30(5): p. 1228-33. 2. Saxon LA: The Subcutaneous Implantable Defibrillator: A New Technology That Raises an Existential Question for the Implantable Cardioverter-Defibrillator. Circulation 2013; 128(9) 938-940. 3. Majithia A, Estes NA, Weinstock J: Advances in Sudden Death Prevention: The Emerging Role of a Fully Subcutaneous Defibrillator. JAMA 2014; 127(3) 188-194. 4. Burke MC, Gold MR, Knight BP, Barr CS, Theuns DA, Boersma LV, Knops RE, Weiss R, Leon AR, Herre JM, Husby M, Stein KM, Lambiase PD: Safety and Efficacy of the Totally Subcutaneous Implantable Defibrillator: 2-Year Results From a Pooled Analysis of the IDE Study and EFFORTLESS Registry. J Am Coll Cardiol 2015; 65(16):1605-15. 5. Weiss R, Knight BP, Gold MR, Leon AR, Herre JM, Hood M, Rashtian M, Burke MC: Safety and efficacy of a totally subcutaneous implantable-cardioverter defibrillator. Circulation 2013; 128(9) 944-953. 6. Lambiase PD, Barr C, Theuns DA, Knops R, Neuzil P, Johansen JB, Hood M, Pedersen S, Kääb S, Murgatroyd F, Reeve HL, Carter N, Boersma L, EFFORTLESS Investigators: Worldwide experience with a totally subcutaneous implantable defibrillator: early results from the EFFORTLESS S-ICD Registry. Eur Heart J 2014; 35(25):1657-65.
7
7. Essandoh MK, Portillo JG, Weiss R, Otey AJ, Zuleta-Alarcon AN, Humeidan ML, Torres JL, Flores AS, Castellon-Larios K, Abdel-Rasoul M, Andritsos MJ, Perez WJ, Stein EJ, Turner KR, Dimitrova GT, Awad H, Bhandary SP, Tripathi RS, Josepha NC, Hummel JD, Augostini RS, Kalbfleisch SJ, Tyler JD, Houmsse M, Daoud EG: Anesthesia care for subcutaneous implantable cardioverter/defibrillator placement: a single-center experience. J Clin Anesth 2016; 31:53–59. 8. Wilkoff BL, Fauchier L, Stiles MK, et al: 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement of optimal implantable cardioverter-defibrillator programming and testing. Heart Rhythm 2016; 13(2): e50-86. 9. Curtis AB: Defibrillation threshold testing in implantable cardioverter-defibrillators: Might less be more than enough? J Am Coll Cardiol 2008; 52(7):557-8. 10. Kutyifa V, Moss AJ: Defibrillation testing is not required during routine ICD implantation. Eur Heart J 2015; 36(25):2508-9. 11. Toh N, Nishii N, Nakamura K, et al: Cardiac dysfunction and prolonged hemodynamic deterioration after implantable cardioverter-defibrillator shock in patients with systolic heart failure. Circ Arrhythm Electrophysiol 2012; 5:898-905. 12. Birnie D, Tung S, Simpson C, et al: Complications associated with defibrillation threshold testing: The Canadian experience. Heart Rhythm 2008; 5(3): 387-390. 13. Frommeyer G, Zumhagen S, Dechering DG, et al: Intraoperative defibrillation testing of subcutaneous implantable cardioverter-defibrillator systems-A simple issue? J Am Heart Assoc 2016; 5(3): e003181
8
14. Friedman DJ, Parzynski CS, Varosy PD, et al: Trends and in-hospital outcomes associated with adoption of the subcutaneous implantable cardioverter defibrillator in the United States. JAMA Cardiol 2016; 1(8):900-911. 15. Wilkoff BL, Fauchier L, Stiles MK, et al: 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing. J. Arrhythm 2016; 32(1):1-28.
9