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Medicare National Coverage Determinations Manual, Part 1
Medicare National Coverage Determinations Manual Chapter 1, Part 1 (Sections 10 – 80.12) Coverage Determinations Table of Contents (Rev. 10838, 06-08-21) Transmittals for Chapter 1, Part 1 Foreword - Purpose for National Coverage Determinations (NCD) Manual 10 - Anesthesia and Pain Management 10.1 - Use of Visual Tests Prior to and General Anesthesia During Cataract Surgery 10.2 - Transcutaneous Electrical Nerve Stimulation (TENS) for Acute Post- Operative Pain 10.3 - Inpatient Hospital Pain Rehabilitation Programs 10.4 - Outpatient Hospital Pain Rehabilitation Programs 10.5 - Autogenous Epidural Blood Graft 10.6 - Anesthesia in Cardiac Pacemaker Surgery 20 - Cardiovascular System 20.1 - Vertebral Artery Surgery 20.2 - Extracranial - Intracranial (EC-IC) Arterial Bypass Surgery 20.3 - Thoracic Duct Drainage (TDD) in Renal Transplants 20.4 – Implantable Cardioverter Defibrillators (ICDs) 20.5 - Extracorporeal Immunoadsorption (ECI) Using Protein A Columns 20.6 - Transmyocardial Revascularization (TMR) 20.7 - Percutaneous Transluminal Angioplasty (PTA) (Various Effective Dates Below) 20.8 - Cardiac Pacemakers (Various Effective Dates Below) 20.8.1 - Cardiac Pacemaker Evaluation Services 20.8.1.1 - Transtelephonic Monitoring of Cardiac Pacemakers 20.8.2 - Self-Contained Pacemaker Monitors 20.8.3 – Single Chamber and Dual Chamber Permanent Cardiac Pacemakers 20.8.4 Leadless Pacemakers 20.9 - Artificial Hearts And Related Devices – (Various Effective Dates Below) 20.9.1 - Ventricular Assist Devices (Various Effective Dates Below) 20.10 - Cardiac -
Cardiac Muscle: Structure and Properties
CARDIOVASCULAR SYSTEM: CARDIAC MUSCLE: STRUCTURE AND PROPERTIES For: Semester II CC2TH/ GEN 2TH Prepared and Compiled By: OLIVIA CHOWDHURY DEPARTMENT OF PHYSIOLOGY SURENDRANATH COLLEGE April 29, 2020 OLIVIA CHOWDHURY •Anatomy of The Heart April 29, 2020 OLIVIA CHOWDHURY •The Layers Of The Heart Three layers: • Epicardium . Pericardium – a double serous membrane . Visceral pericardium (Next to heart) . Parietal pericardium (Outside layer) . Serous fluid fills the space between the layers of pericardium . Connective tissue layer • Myocardium . Middle layer . Mostly cardiac muscle • Endocardium . Inner layer . Endothelium April 29, 2020 OLIVIA CHOWDHURY • The Heart Valves Allows blood to flow in only one direction Four valves: Atrioventricular valves– between atria and ventricles Bicuspid/ Mitral valve between LA and LV Tricuspid valve between RA and RV Semilunar valves between ventricles and arteries Pulmonary semilunar valve Aortic semilunar valve April 29, 2020 OLIVIA CHOWDHURY •Direction Of Blood Flow In The Heart April 29, 2020 OLIVIA CHOWDHURY Right side of the heart: • receives venous blood from systemic circulation via superior and inferior vena cava into right atrium • pumps blood to pulmonary circulation from right ventricle Left side of the Heart: • receives oxygenated blood from pulmonary veins • pumps blood into systemic circulation April 29, 2020 OLIVIA CHOWDHURY •The Cardiac Muscle Myocardium has three types of muscle fibers: Muscle fibers which form contractile unit of heart Muscle fibers which form the pacemaker Muscle fibers which form conductive system April 29, 2020 OLIVIA CHOWDHURY •The Cardiac Muscle Striated and resemble the skeletal muscle fibre Sarcomere is the functional unit Sarcomere of the cardiac muscle has all the contractile proteins, namely actin, myosin, troponin tropomyosin. -
Are Ryanodine Receptors Important for Diastolic Depolarization in Heart?
ARE RYANODINE RECEPTORS IMPORTANT FOR DIASTOLIC DEPOLARIZATION IN HEART? A Dissertation submitted in partial fulfillment of the requirement for the Degree of Doctor of Medicine in Physiology (Branch – V) Of The Tamilnadu Dr. M.G.R Medical University, Chennai -600 032 Department of Physiology Christian Medical College, Vellore Tamilnadu April 2017 Ref: …………. Date: …………. CERTIFICATE This is to certify that the thesis entitled “Are ryanodine receptors important for diastolic depolarization in heart?” is a bonafide, original work carried out by Dr.Teena Maria Jose , in partial fulfillment of the rules and regulations for the M.D – Branch V Physiology examination of the Tamilnadu Dr. M.G.R. Medical University, Chennai to be held in April- 2017. Dr. Sathya Subramani, Professor and Head Department of Physiology, Christian Medical College, Vellore – 632 002 Ref: …………. Date: …………. CERTIFICATE This is to certify that the thesis entitled “Are ryanodine receptors important for diastolic depolarization in heart?” is a bonafide, original work carried out by Dr.Teena Maria Jose , in partial fulfillment of the rules and regulations for the M.D – Branch V Physiology examination of the Tamilnadu Dr. M.G.R. Medical University, Chennai to be held in April- 2017. Dr. Anna B Pulimood, Principal, Christian Medical College, Vellore – 632 002 DECLARATION I hereby declare that the investigations that form the subject matter for the thesis entitled “Are ryanodine receptors important for diastolic depolarization in heart?” were carried out by me during my term as a post graduate student in the Department of Physiology, Christian Medical College, Vellore. This thesis has not been submitted in part or full to any other university. -
Atrioventricular Conduction in Patients with Clinical Indications for Transvenous Cardiac Pacing1
British Heart Journal, 1975, 37, 583-592. Atrioventricular conduction in patients with clinical indications for transvenous cardiac pacing1 Stafford I. Cohen, L. Kent Smith, Julian M. Aoresty, Panagiotis Voukydis, and Eugene Morkin From the Cardiac Unit, Department of Medicine, Beth Israel Hospital and Harvard Medical School, Boston, Massachusetts, U.S.A. Eighty patients with clinical indications for cardiac pacing had atrioventricular conduction analysed by His bundle study. The indicationsfor cardiac pacing included high grade atrioventricular block, sick sinus node syndrome without tachycardia, bradycardia-tachycardia syndrome, unstable bilateral bundle-branch block, and uncontrolled ventricular irritability. Complete heart block, Wenckebach block (Mobitz I), and 2:i block were notedproximal and distal to the His bundle. Mobitz II block only occurred distal to the His bundle. Ofspecial interest were the high incidence ofdistal conduction abnormalities by His bundle analysis (40/80, 5o%), the re-establishment ofnormal atrio- ventricular conduction in acutely ill patients with recent evidence of heart block, and the high incidence of intraventricular conduction disturbances on standard electrocardiogram (48/8o, 60%). Intensive study of atrioventricular conduction by occurring electrophysiological data in this large His bundle analysis has been performed in a variety group of patients in clinical need of pacemakers of patient populations. In many instances studies constitutes the substance of this report. The data were electively undertaken in patients who had should be representative of the cardiac conduction never been threatened by a compromising cardiac abnormalities which present in a general hospital. arrhythmia. In addition, abnormalities of atrio- ventricular conduction were frequently achieved by Subjects and methods pacemaker-induced acceleration of the atrial rate. -
The Miniaturization of Cardiac Implantable Electronic Devices: Advances in Diagnostic and Therapeutic Modalities
micromachines Review The Miniaturization of Cardiac Implantable Electronic Devices: Advances in Diagnostic and Therapeutic Modalities Richard G. Trohman *, Henry D. Huang and Parikshit S. Sharma Section of Electrophysiology, Arrhythmia and Pacemaker Services, Division of Cardiology, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA; [email protected] (H.D.H.); [email protected] (P.S.S.) * Correspondence: [email protected]; Tel.: +1-312-942-2887 Received: 26 August 2019; Accepted: 17 September 2019; Published: 21 September 2019 Abstract: The Fourth Industrial Revolution, characterized by an unprecedented fusion of technologies that is blurring the lines between the physical, digital, and biological spheres, continues the trend to manufacture ever smaller mechanical, optical and electronic products and devices. In this manuscript, we outline the way cardiac implantable electronic devices (CIEDs) have evolved into remarkably smaller units with greatly enhanced applicability and capabilities. Keywords: implantable cardioverter defibrillators; cardiac pacing; cardiac resynchronization therapy; implantable heart failure sensor; implantable loop recorder 1. Introduction The Fourth Industrial Revolution [1], characterized by an unprecedented fusion of technologies that is blurring the lines between the physical, digital, and biological spheres, continues the trend to manufacture ever smaller mechanical, optical and electronic products and devices [2]. In this manuscript, we outline the way cardiac implantable electronic devices (CIEDs) have evolved into remarkably smaller units with greatly enhanced applicability and capabilities. 2. Prevention of Sudden Death The current annual incidence of sudden cardiac death in the United States is in the range of 180,000 to 450,000 per year [3,4]. Although the prevalence of malignant ventricular arrhythmias as the etiology has declined, they remain the most common cause of cardiac arrest [3]. -
An Interesting Case of Acute Asymptomatic Lead Perforation of a Permanent Cardiac Pacemaker
Open Access Case Report DOI: 10.7759/cureus.13334 An Interesting Case of Acute Asymptomatic Lead Perforation of a Permanent Cardiac Pacemaker Anunay Gupta 1 , Sourabh Agstam 1 , Tushar Agarwal 1 , Sunil Verma 2 1. Cardiology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, IND 2. Cardiology, All India Institute of Medical Sciences, New Delhi, IND Corresponding author: Sunil Verma, [email protected] Abstract Acute complications of pacemaker implantation such as lead dislodgement, pneumothorax, and myocardial perforation are not uncommon. Management of these usually requires reintervention. We herein describe lead perforation after a single chamber pacemaker implantation, which was successfully managed conservatively. This case underscores that vigilant monitoring post lead perforation can avoid a redo procedure. Categories: Cardiac/Thoracic/Vascular Surgery, Cardiology, Radiology Keywords: impending pericardial effusion, pacemaker lead perforation, pacemaker lead displacement, pacemaker complication Introduction Acute complications such as lead dislodgement, pneumothorax, and myocardial perforation are not uncommon after pacemaker implantation. Lead perforation can be either early or late, and lead can perforate through the myocardium, into the epicardial space, pericardium, or chest wall [1]. Such perforations can sometimes be clinically occult and not accompanied by symptoms such as pain or pericardial effusion [2]. A chest X-ray in two different views is useful in demonstrating perforation but is limited by its inability to differentiate between the ventricular cavity, myocardium, and pericardium. A cardiac computed tomography (CT) is more reliable for lead tip identification. Such a case is usually managed by repositioning the leads at the desired position, at the risk of pericardial effusion, infection, and prolonged admission. -
Lab 2 Intrinsic Cardiac Conduction System Spring 2016 V10.Pdf
Lab 2 The Intrinsic Cardiac Conduction System 1/23/2016 MDufilho 1 Figure 18.13 Intrinsic cardiac conduction system and action potential succession during one heartbeat. Superior vena cava Right atrium 1 The sinoatrial (SA) node (pacemaker) generates impulses. Pacemaker potential Internodal pathway 2 The impulses Left atrium SA node pause (0.1 s) at the atrioventricular (AV) node. Atrial muscle 3 The Subendocardial atrioventricular conducting (AV) bundle network connects the atria (Purkinje fibers) AV node to the ventricles. 4 The bundle branches Pacemaker Ventricular conduct the impulses Inter- potential muscle through the ventricular interventricular septum. septum Plateau 5 The subendocardial conducting network depolarizes the contractile 0 100 200 300 400 cells of both ventricles. Milliseconds Anatomy of the intrinsic conduction system showing the sequence of Comparison of action potential shape at electrical excitation various locations 1/23/2016 MDufilho 2 Video • Conducting System Of The Heart 1/23/2016 MDufilho 3 Figure 18.12 Pacemaker and action potentials of pacemaker cells in the heart. 1 Pacemaker potential This slow depolarization is due to both opening of Na+ channels and closing of K+ channels. Notice that the membrane potential is Action Threshold never a flat line. +10 potential 0 2 Depolarization The action –10 potential begins when the 2 2 pacemaker potential reaches –20 threshold. Depolarization is due –30 3 3 to Ca2+ influx through Ca2+ –40 channels. –50 3 Repolarization is due to 1 1 2+ –60 Pacemaker Ca channels inactivating and potential K+ channels opening. This allows –70 + Membrane potential(mV) K efflux, which brings the membrane potential back to its most negative voltage. -
Cardiac Pacemaker
Thorax: first published as 10.1136/thx.25.3.267 on 1 May 1970. Downloaded from Thorax (1970), 25, 267. Long-term evaluation of the General Electric cardiac pacemaker DONALD R. KAHN, MARVIN M. KIRSH, SATHAPORN VATHAYANON, PARK W. WILLIS, III, JOSEPH A. WALTON, KAREN McINTOSH, PAULINE W. FERGUSON, and HERBERT SLOAN Department of Surgeir and Medicine, University of Michigan Medical Center, Ann Arbor, MI 48104 A review of General Electric (G.E.) electronic cardiac pacemakers for symptomatic complete A-V heart 'block in two sequential three-year periods at the University of Michigan Medical Center indicates that there has been no increase in the useful life of these units. With G.E. epicardiall pacemakers failure occurred after an average of 12 months. In the early years the major cause of failure was wire breakage, and the later major cause was battery exhaustion or component failure. Exit block was a major complication. There was no improvement when G.E. catheter pacemakers were used instead of the epicardial type. The Medtronic catheter pace- makers lasted longer, with fewer battery and component failures and no instances of exit block. Although infection was more common with Medtronic pacemakers, secondary to erosion of the power unit or the catheter through the skin, it may be that this complication could be eliminated by locating the battery box beneath the latissimus dorsi muscle in the axilla and by careful catheter placement to avoid pressure necrosis and subsequent cutaneous perforation. http://thorax.bmj.com/ The treatment of complete atrioventricular heart pacemaker has been improved in design and con- block by the operative implantation of electronic struction enough to improve its function in the cardiac pacemakers has prolonged the life of many clinical setting. -
Mechanisms Underlying the Cardiac Pacemaker: the Role of SK4 Calcium-Activated Potassium Channels
npg Acta Pharmacologica Sinica (2016) 37: 82–97 © 2016 CPS and SIMM All rights reserved 1671-4083/16 www.nature.com/aps Review Mechanisms underlying the cardiac pacemaker: the role of SK4 calcium-activated potassium channels David WEISBROD, Shiraz Haron KHUN, Hanna BUENO, Asher PERETZ, Bernard ATTALI* Department of Physiology & Pharmacology, Sackler Faculty of Medicine, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel The proper expression and function of the cardiac pacemaker is a critical feature of heart physiology. The sinoatrial node (SAN) in human right atrium generates an electrical stimulation approximately 70 times per minute, which propagates from a conductive network to the myocardium leading to chamber contractions during the systoles. Although the SAN and other nodal conductive structures were identified more than a century ago, the mechanisms involved in the generation of cardiac automaticity remain highly debated. In this short review, we survey the current data related to the development of the human cardiac conduction system and the various mechanisms that have been proposed to underlie the pacemaker activity. We also present the human embryonic stem cell- derived cardiomyocyte system, which is used as a model for studying the pacemaker. Finally, we describe our latest characterization of the previously unrecognized role of the SK4 Ca2+-activated K+ channel conductance in pacemaker cells. By exquisitely balancing the inward currents during the diastolic depolarization, the SK4 channels appear to play a crucial role in human cardiac automaticity. Keywords: cardiac pacemaker; sinoatrial node; SK4 K+ channel; Ca2+ clock model; voltage clock model Acta Pharmacologica Sinica (2016) 37: 82−97; doi: 10.1038/aps.2015.135 Introduction studying the pacemaker, and the most recent characterization Normal cardiac function depends on the adequate timing of of the previously unrecognized role of the SK4 Ca2+-activated excitation and contraction in the various regions of the heart K+ channel conductance in pacemaker cells. -
Cardiovascular Physiology
Introductory Human Physiology © Copyright Emma Jakoi CV 1. HEART ELECTRICAL ACTIVTY Emma Jakoi, Ph.D. LEARNING OBJECTIVES 1. Describe the conduction system of the heart 2. Explain spontaneous electrical activity (pacemaker) in cardiac muscle. 3. Explain action potentials of ventricular cardiac muscle. 4. Explain the cardiac conduction system, pacemakers, and regulation of heart rate by the autonomic nervous system. 5. Explain the ECG and its correspondence to the cardiac action potential (AP). EXCITATION IN CARDIAC MUSCLE The cardiovascular system transports blood containing oxygen, carbon dioxide, nutrients and wastes, between the environment and the cells of the body. It consists of a heart (pump) and blood vessels which deliver nutrients to the tissues (arteries) and ferry waste products away from the tissues (veins). The heart is a muscular organ (Fig 1) which can contract in a rhythmic manner without direct stimulus from the nervous system. Each heart beat begins with the flow of ions across the plasma membrane of the cardiac muscle cell. This current is generated in specialized cells called pacemaker cells. The impulse from the pacemaker cells flows in a unidirectional manner through out the heart via specialized conducting tissue (Fig 1) and into the heart muscle. The electrical impulse results in mechanical contraction of the cardiac muscle through a series of intracellular events involving calcium. Figure 1. Electrical conduction within the heart starts at the sinoatrial (SA) node and passes sequentially to the atriaventricular (AV) node, Bundle of His, left and right bundle branches, and the Purkinje fibers. So the electrical activity moves from the base (A-V junction) to the apex (tip of ventricle) distant from the atria and then sweeps up the sides of the ventricles towards the base. -
On the Evolution of the Cardiac Pacemaker
Journal of Cardiovascular Development and Disease Review On the Evolution of the Cardiac Pacemaker Silja Burkhard 1, Vincent van Eif 2, Laurence Garric 1, Vincent M. Christoffels 2 and Jeroen Bakkers 1,3,* 1 Hubrecht Institute-KNAW and University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands; [email protected] (S.B.); [email protected] (L.G.) 2 Department of Medical Biology, Academic Medical Center Amsterdam, 1105 AZ Amsterdam, The Netherlands; [email protected] (V.v.E.); [email protected] (V.M.C.) 3 Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands * Correspondence: [email protected]; Tel.: +31-302121892 Academic Editors: Robert E. Poelmann and Monique R. M. Jongbloed Received: 24 March 2017; Accepted: 24 April 2017; Published: 27 April 2017 Abstract: The rhythmic contraction of the heart is initiated and controlled by an intrinsic pacemaker system. Cardiac contractions commence at very early embryonic stages and coordination remains crucial for survival. The underlying molecular mechanisms of pacemaker cell development and function are still not fully understood. Heart form and function show high evolutionary conservation. Even in simple contractile cardiac tubes in primitive invertebrates, cardiac function is controlled by intrinsic, autonomous pacemaker cells. Understanding the evolutionary origin and development of cardiac pacemaker cells will help us outline the important pathways and factors involved. Key patterning factors, such as the homeodomain transcription factors Nkx2.5 and Shox2, and the LIM-homeodomain transcription factor Islet-1, components of the T-box (Tbx), and bone morphogenic protein (Bmp) families are well conserved. -
Symbiotic Cardiac Pacemaker
ARTICLE https://doi.org/10.1038/s41467-019-09851-1 OPEN Symbiotic cardiac pacemaker Han Ouyang 1,2,6, Zhuo Liu1,3,6, Ning Li4,6, Bojing Shi1,3,6, Yang Zou1,2, Feng Xie4,YeMa4, Zhe Li1,2,HuLi1,3, Qiang Zheng 1,2, Xuecheng Qu1,2, Yubo Fan3, Zhong Lin Wang 1,2,5, Hao Zhang1,4 & Zhou Li 1,2 Self-powered implantable medical electronic devices that harvest biomechanical energy from cardiac motion, respiratory movement and blood flow are part of a paradigm shift that is on the horizon. Here, we demonstrate a fully implanted symbiotic pacemaker based on an implantable triboelectric nanogenerator, which achieves energy harvesting and storage as 1234567890():,; well as cardiac pacing on a large-animal scale. The symbiotic pacemaker successfully corrects sinus arrhythmia and prevents deterioration. The open circuit voltage of an implantable triboelectric nanogenerator reaches up to 65.2 V. The energy harvested from each cardiac motion cycle is 0.495 μJ, which is higher than the required endocardial pacing threshold energy (0.377 μJ). Implantable triboelectric nanogenerators for implantable medical devices offer advantages of excellent output performance, high power density, and good durability, and are expected to find application in fields of treatment and diagnosis as in vivo symbiotic bioelectronics. 1 CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-Nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, 100083 Beijing, China. 2 School of Nanoscience and Technology, University of Chinese Academy of Sciences, 100049 Beijing, China. 3 Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, 100083 Beijing, China.