Unreferenced date December 2009 Merge Myocardial stunning date March 2009 In cardiology stunned myocardium is a state when some section of the myocardium corresponding to area of a major coronary occlusion shows a form of contractile abnormality. This is a segmental dysfunction which persists for a variable period of time, about two weeks, even after ischemia has been relieved by for instance angioplasty or coronary artery bypass surgery . In this situation, while myocardial blood flow MBF returns to normal, function is still depressed for a variable period of time. Clinical situations of stunned myocardium are acute myocardial infarction AMI after percutaneous transluminal coronary angioplasty PTCA after cardiac surgery neurogenic stunned myocardium following an acute cerebrovascular event such as a subarachnoid hemorrhage See also Hibernating myocardium Myocardial scarring Myocardial infarction DEFAULTSORT Stunned Myocardium Category Ischemic heart diseases ... more details
In cardiology , hibernating myocardium is a state when some segments of the myocardium exhibit abnormalities of contractile function. ref name pmid9664095 cite journal author Wijns W, Vatner SF, Camici PG title Hibernating myocardium journal N. Engl. J. Med. volume 339 issue 3 pages 173 81 year 1998 month July pmid 9664095 doi 10.1056 NEJM199807163390307 url http content.nejm.org cgi pmidlookup?view short&pmid 9664095&promo ONFLNS19 ref These abnormalities can be visualised during echocardiography or ventriculography . The finding of a perfusion or metabolic mismatch between PET FDG and PET NH3 is indicative of decreased metabolism. The wall of the affected segments is hypo , a , or dyskinetic. The phenomenon is highly significant clinically because it usually manifests itself in the setting of chronic ischemia , that is potentially reversible by Revascularization revascularisation via cardiac catheterization. The regions of myocardium are still viable and can restore its function. There develops a new steady state between myocardial blood flow MBF and myocardial function, MBF reduced and in consequence function is reduced too. The clinical situations where one can expect hibernating myocardium are chronic stable Angina pectoris angina unstable angina silent ischemia after myocardial infarction AMI See also stunned myocardium myocardial scarring References Reflist Heart diseases Category Ischemic heart diseases ... more details
Ventriculotomy is a medical procedure in which a portion of a patient s heart is resected in order to correct for an abnormal enlargement of the myocardium . Such an enlargement is usually the result of an idiopathic cardiomyopathy . Citation needed date February 2010 Category Cardiac procedures Medical stub ... more details
Myocardial ischemia is an imbalance between myocardium myocardial oxygen supply and demand. Left untreated, it results in angina pectoris , myocardial stunning , Hibernating myocardium myocardial hibernation , ischemic preconditioning , postconditioning, or under the most severe instances, acute coronary syndrome and myocardial infarction . Myocardial ischemia is the pathological state underlying ischaemic heart disease . References Hurst s The Heart, 12th edition, 2007. Category Medical terms Category Ischemic heart diseases medical stub ... more details
Normally, the pacemaker of the heart that is responsible for triggering each heart beat ventricular contraction is the SA Sino Atrial node. However, if the ventricle does not receive triggering signals at a rate high enough, the ventricular myocardium itself becomes the pacemaker escape rhythm . This is called Idioventricular Rhythm. The rate is usually 20 40 bpm. If the rate is 40 bpm, it is called accelerated idioventricular rhythm . The rate of 20 40 is the intrinsic automaticity of the ventricular myocardium. This is the backup plan or redundancy built into the body Category Cardiac dysrhythmia ... more details
A coronary occlusion is the partial or complete obstruction of blood flow in a coronary artery . This condition may cause a myocardial infarction heart attack . In some patients coronary occlusion causes only mild pain, tightness or vague discomfort which may be ignored the myocardium is however damaged. Category Heart diseases disease stub ... more details
Ectopic beat or cardiac ectopy is a disturbance of the cardiac rhythm frequently related to the electrical conduction system of the heart , in which beats arise from fiber or group of fibers outside the region in the myocardium heart muscle ordinarily responsible for impulse formation, i.e., the Sinus node . ref DorlandsDict one 000012106 ectopic beat ref Some patients describe this experience as a flip or a jolt in the chest, while others report dropped or missed beats. Such extrasystoles are more common during periods of stress or debility they may also be triggered by consumption of some food like alcohol, strong cheese or chocolates, etc. It is a form of cardiac arrhythmia in which Ectopic pacemaker ectopic foci within either Ventricle heart ventricular or Atrium heart atrial wikt myocardium myocardium , or from finer branches of the electric transduction system, cause additional beats of the heart . Some medication s may worsen the condition. See also Ventricular escape beat Junctional escape beat Arrhythmia Origin of impulse Palpitation References reflist See also Ectopia disambiguation Heart diseases Category Cardiac dysrhythmia disease stub ... more details
SFHAM single fibre based heart activity model is a physical model describing the electric activity of the left ventricle of the heart during its depolarisation . It facilitates a precise analysis of electric potential s of different parts of the ventricle. ref http www.medengphys.com article S1350 4533 09 00182 9 abstract Janicki JS, W. Leo ski W, Jagielski J. Partial potentials of selected cardiac muscle regions and heart activity model based on single fibres , Medical Engineering & Physics ref Main principles of the model The SFHAM model is based on the following principles Each part of the cardiac muscle interventricular septum , Anterior wall of heart anterior wall , Diaphragmatic surface of heart inferior wall , lateral wall, posterior wall is the source of independent instantaneous potential. Electric potential coming from a particular part of the myocardium is the result of variation in electric charge density including endocardium , myocardium M cells and epicardium . QRS unit is the result of the sum of all instantaneous potentials generated during depolarization of particular parts of myocardium. The value of instantaneous potential depends on he quality and activity of particular parts of the ventricle walls. Time changes in the value of the potentials distribution occurring on the surface of the chest depend on physiological and pathological factors. Electrical activity of each part of the myocardium of a healthy individual forms a constant contribution expressed in percentage into the entire activity of the myocardium. The model constitutes a theoretical basis for SATRO ECG being a system to Non invasive medical non invasive diagnosing facilitating early detection coronary heart disease ischemic changes in the heart . References Reflist Bibliography Janicki JS, Leo ski W, Jagielski J. Partial potentials of selected cardiac muscle regions and heart activity model based on single fibres. Medical Engineering & Physics, 31 2009 1276 1282 http www.medengphys ... more details
Carditis is the inflammation of the heart ref DorlandsDict two 000017437 carditis ref or its surroundings. It is usually studied and treated by specifying it as Pericarditis is the inflammation of the pericardium Myocarditis is the inflammation of the heart heart muscle Endocarditis is the inflammation of the endocardium Reflux carditis refers to a possible outcome of esophageal reflux also known as Gastroesophageal reflux disease GERD Pancarditis inflammation of the entire heart the epicardium and the myocardium and the endocardium carditis inflammation of the heart References reflist Heart diseases Inflammation Category Heart diseases disease stub de Karditis it Pancardite pt Cardite fi Syd ntulehdus ... more details
Cellular cardiomyoplasty , or cell based cardiac repair, is a new potential therapeutic modality in which progenitor cell s are used to repair regions of damaged or necrotic myocardium . The ability of transplanted progenitor cells to improve function within the failing heart has been shown in both experimental animal models and human clinical trials. ref cite journal author Murry CE title Cell Based Cardiac Repair Reflections at the 10 Year Point journal Circulation volume 112 issue 20 pages 3174 83 year 2005 doi 10.1161 CIRCULATIONAHA.105.546218 ref References reflist Category Cardiac procedures Category Regenerative biomedicine Treatment stub cell biology stub ... more details
the SA and AV nodes stimulate the Myocardium . Time ordered stimulation of the myocardium allows ... Cardiac neurons innervating the myocardium bear limited similarities to those of skeletal muscle ... to the ventricular myocardium. The pathway of the nerve impulse pass through the heart ... impulse pass from SA node to the ventricular myocardium is 0.19 seconds. Microscopically, the wave ..., electrical impulses propagate freely between communicating cells via gap junctions, so that the myocardium ... of the myocardium. While normally advantageous, this property can be detrimental as it potentially ... damaged or dying tissue in the myocardium, which then no longer participate in synchronous myocardial ... Bachmann s bundle to the left atrium, stimulating the myocardium of both atria to contract. The conduction ... myocardium. This allows pre ejaculating of the chordae tendinae, increasing the resistance to flow through the mitral valve during left ventricular contraction. Purkinje fibers ventricular myocardium ... through the ventricular myocardium produces the QRS complex on the ECG. Ventricular repolarization ... more details
of short axis images, only the longitudinal compression of the myocardium from base to apex is measured. On the other hand, circumferential shortening of the myocardium can be measured in the long axis ... more details
contraction of the ventricle heart ventricular myocardium Systole medicine systole , the subendocardial coronary vessels the vessels that enter the myocardium are compressed due to the high intraventricular ... of the myocardium receives dual blood supply. These junctions are called anastomoses . If one ... blood to the myocardium. However this can only occur if the atheroma progresses slowly, giving the anastomoses ... more details
Sinoatrial arrest also known as sinus arrest or sinus pause is a medical condition wherein the sinoatrial node of the heart transiently ceases to generate the electrical impulses that normally stimulate the myocardium myocardial tissues to contract and thus the heart to beat. It is defined as lasting from 2.0 seconds to several minutes. ref http www.uptodate.com contents sinoatrial nodal pause arrest and exit block ref Since the heart contains multiple pacemakers, this interruption of the cardiac cycle generally lasts only a few seconds before another part of the heart, such as the atrio ventricular junction or the Ventricle heart ventricle s, begins pacing and restores the heart action. This condition can be detected on an electrocardiogram ECG as a brief period of irregular length with no electrical activity before either the sinoatrial node resumes normal pacing, or another pacemaker begins pacing. If a pacemaker other than the sinoatrial node is pacing the heart, this condition is known as an escape rhythm . If no other pacemaker begins pacing during an episode of sinus arrest it becomes a cardiac arrest . This condition is sometimes confused with sinoatrial block , a condition in which the pacing impulse is generated, but fails to conduct through the myocardium . Differential diagnosis of the two conditions is possible by examining the exact length of the interruption of cardiac activity. If the next available pacemaker takes over, it is in the following order 1. Atrial escape rate 60 80 originates within Atrium heart atria , not sinus node normal P morphology is lost . 2. Junctional escape rate 40 60 originates near the AV node a normal P wave is not seen, may occasionally see a retrograde P wave. 3. Ventricular escape rate 20 40 originates in ventricular conduction system no P wave, wide, abnormal QRS . Treatment includes stop medications that suppress the sinus node beta blocker , CCB , digitalis may need pacing. References reflist cite web url http bmj.bmjj ... more details
Infobox Vein Name PAGENAME Latin venae cardiacae minimae venae cordis minimae GraySubject 166 GrayPage 643 Image Caption Image2 Caption2 DrainsFrom DrainsTo Artery MeshName MeshNumber The smallest cardiac veins or Thebesian veins are minute valveless vein s in the walls of all four heart chambers. They are most abundant in the right atrium and least in the left ventricle . They drain the myocardium ref name AgurDalley2009 cite book author1 A. M. R. Agur author2 Arthur F. Dalley title Grant s atlas of anatomy url http books.google.com books?id H20V4pCpACYC&pg PA53 accessdate 31 October 2010 year 2009 publisher Lippincott Williams & Wilkins isbn 9780781770552 pages 53 ref and pass through the endocardium endocardial layer to empty directly into the right atrium. The openings of the chambers are called the foramina venarum minimarum . The Thebesian venous network is considered an alternative secondary pathway of venous drainage of the myocardium . It is named after German anatomist Adam Christian Thebesius , who described them in a 1708 treatise called Disputatio medica inauguralis de circulo sanguinis in corde . ref WhoNamedIt synd 4013 ref ref A. C. Thebesius. Disputatio medica inauguralis de circulo sanguinis in corde. Doctoral dissertation, Leiden, 1708. ref References reflist External links http www.gpnotebook.co.uk simplepage.cfm?ID 107347908 GPnotebook venae cordis minimae http www.medscape.com viewarticle 550354 2 Medscape Today Coronary Venous System Veins of the thorax and vertebral column Category Cardiac anatomy Cardiology stub pl y y najmniejsze serca ... more details
Infobox Anatomy Name Epicardium Latin lamina visceralis pericardii serosi GraySubject GrayPage Image Gray968.png Caption A transverse section of the thorax, showing the contents of the middle and the posterior mediastinum. The pleural and pericardial cavities are exaggerated since normally there is no space between parietal and visceral pleura and between pericardium and heart. Image2 Caption2 Precursor System Artery Vein Nerve Lymph MeshName MeshNumber DorlandsPre l 02 DorlandsSuf 12476850 Epicardium describes the outer layer of heart tissue from Greek language Greek epi outer, cardium heart . When considered as a part of the pericardium , it is the inner layer, or visceral pericardium , continuous with the serous layer. Its largest constituent is connective tissue and functions as a protective layer. The visceral pericardium apparently produces the pericardial fluid , which lubricates motion between the inner and outer layers of the pericardium . During ventricular contraction, the wave of depolarization moves from endocardial to epicardial surface. See also Myocardium The middle muscle layer of the heart Endocardium The innermost layer of the heart External links http sprojects.mmi.mcgill.ca embryology cvs heart tube.html UMichAtlas ht pericard2 MRI of chest, lateral view Heart Category Cardiac anatomy circulatory stub az Epikard bs Epikard ca Epicardi de Epikard es Epicardio fr picarde it Epicardio hu Epicardium nl Epicard pl Nasierdzie ro Epicard sk Epikard ... more details
Infobox disease ICD10 ICD10 I 42 9 i 30 Tachycardia induced cardiomyopathy , also known as chronotropic cardiomyopathy and tachycardiomyopathy , is a weakening of the myocardium the muscle of the heart that is due to prolonged periods of a tachycardia fast heart rate . The rate and duration of the elevation in heart rate necessary to cause a cardiomyopathy is unclear and is likely dependent on a number of unknown factors. Treatment The primary treatment for a tachycardia induced cardiomyopathy is correct the underlying tachycardia. Supportive agents such as beta blocker s and ACE inhibitor s Angiotensin II receptor antagonist angiotensin receptor blockers are of benefit to try to prevent remodeling of the left ventricle . If the tachycardia can be abolished, the heart muscle can recover after some time. ref cite journal author Calo L, Sciarra L, Scioli R, Lamberti F, Loricchio ML, Pandozi C, Santini M. title Recovery of cardiac function after ablation of atrial tachycardia arising from the tricuspid annulus. journal Ital Heart J. year 2005 volume 6 issue 8 pages 652 7 pmid 16161499 ref Not only is there a need to control the tachycardia that is responsible for causing tachycardia induced cardiomyopathy, but also treating underlying conditions that cause tachycardia. For instance, treatment of hyperthyroidism can also lead to reversal of tachycardia induced cardiomyopathy. See also Cardiomyopathy Congestive heart failure References reflist Category Cardiomyopathy disease stub ... more details
Bracht Wachter bodies are a finding in infective endocarditis ref DorlandsDict one 000013555 Bracht W chter bodies ref consisting of yellow white miliary spots in the myocardium . Histopathology Histologically , these are collections of chronic inflammatory cells, mainly lymphocytes ref name urlDefinition Bracht Wachter lesion from Online Medical Dictionary cite web url http cancerweb.ncl.ac.uk cgi bin omd?Bracht Wachter lesion title Definition Bracht Wachter lesion from Online Medical Dictionary format work accessdate 2008 12 22 ref and histiocytes . History They were described by two Germans, Erich Franz Eugen Bracht , a pathologist and obstetrician gynecologist, and Hermann Julius Gustav W chter , a physician. ref Bracht, E., and Wachter Beitrage zur Aetiologie und pathologischen Anatomic der Myocarditis rheumatica, Deutsch. Arch. f. klin. Med., Leipz., 1909, xcvi, 493. ref Related findings Other findings in infective endocarditis are Osler s nodes Janeway lesions Roth s spots Flea bitten kidneys pyemic spots References reflist Category Histopathology pathology stub Eponymous medical signs for circulatory and respiratory systems ... more details
enzyme Name fatty acyl ethyl ester synthase EC number 3.1.1.67 CAS number IUBMB EC number 3 1 1 67 GO code 0030339 image width caption In enzymology , a fatty acyl ethyl ester synthase EC number 3.1.1.67 is an enzyme that catalysis catalyzes the chemical reaction a long chain fatty acyl ethyl ester H sub 2 sub O math rightleftharpoons math a long chain fatty acid ethanol Thus, the two substrate biochemistry substrates of this enzyme are long chain fatty acyl ethyl ester and water H sub 2 sub O , whereas its two product chemistry products are long chain fatty acid and ethanol . This enzyme belongs to the family of hydrolase s, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is long chain fatty acyl ethyl ester acylhydrolase . This enzyme is also called FAEES . References reflist 1 cite journal author Mogelson S, Lange LG date 1984 title Nonoxidative ethanol metabolism in rabbit myocardium purification to homogeneity of fatty acyl ethyl ester synthase journal Biochemistry. volume 23 pages 4075&ndash 81 pmid 6487591 doi 10.1021 bi00313a010 issue 18 hydrolase stub Category EC 3.1.1 Category Enzymes of unknown structure ... more details
The endocardial heart tubes are paired regions in the embryo that appear in its ventral pole by the middle of the third week of gestation and consist of precursor cells for the development of the embryonic heart . The endocardial heart tubes derive from the Lateral plate mesoderm visceral mesoderm and initially are formed by a confluence of angioblast ic blood vessels on either side of the embryonic midline. The endocardial tubes have an intimate proximity to the foregut or pharyngeal endoderm . ref cite book title Cardiac development last Kirby first Margaret L. authorlink coauthors year 2007 publisher Oxford University Press location isbn 019517819X page 119 pages url http books.google.com books?id fjhCQ QbtbsC accessdate 20 April 2011 ref As folding of the embryo in the horizontal plane initiates in the 4th week of gestation, the endocardial tubes meet in the midline to form the primitive heart tube , which will eventually develop into the histologically definitive endocardium . The myocardium forms from mesoderm cells surrounding the heart tube, while the epicardium develops from other cells, most likely from neural crest cells. References reflist External links EmbryologyTemple Heart98 heart97a sld018 EmbryologyTemple Heart98 heart97a sld019 Development of circulatory system Category Embryology of cardiovascular system Anatomy stub ... more details
effect. In vivo Sympathetic nervous system sympathetic outflow within the myocardium is probably ... fibers . Parasympathetic inflow within the myocardium is probably best described by influence of the vagus ... more details
Infobox Anatomy Name PAGENAME Latin GraySubject 138 GrayPage 535 Image Gray493.png Caption Interior of right side of heart. Image2 Caption2 Precursor System Artery Vein Nerve Lymph MeshName MeshNumber DorlandsPre DorlandsSuf The endocardium is the innermost layer of tissue that lines the chambers of the heart. Its Cell biology cells are embryology embryologically and biology biologically similar to the endothelium endothelial cells that line blood vessel s. The endocardium underlies the much more voluminous myocardium , the muscular tissue responsible for the contraction of the heart. The outer layer of the heart is termed epicardium and the heart is surrounded by a small amount of fluid enclosed by a fibrous sac called the pericardium . Function Recently, it has become evident that the endocardium, which is primarily made up of endothelial cells, controls myocardial function. This modulating role is separate from the homeometric and heterometric regulatory mechanisms that control myocardial contractility. Moreover, the endothelium of the myocardial heart muscle capillaries, which is also closely appositioned to the cardiomyocytes heart muscle cells is involved in this modulatory role. Thus, the cardiac endothelium both the endocardial endothelium and the endothelium of the myocardial capillaries controls the development of the heart in the embryo as well as in the adult, for example during hypertrophy. Additionally, the contractility and electrophysiological environment of the cardiomyocyte are regulated by the cardiac endothelium. The endocardial endothelium may also act as a kind of blood heart barrier analogous to the blood brain barrier , thus controlling the ionic composition of the extracellular fluid in which the cardiomyocytes bathe. Role in disease In myocardial infarction , ischemia of the myocardium can extend to the endocardium, disrupting the inner lining of the heart transmural infarction . Less extensive infarctions are often subendocardial and do no ... more details
Infobox Artery Name PAGENAME Latin ramus interventricularis anterior arteriae coronariae sinistrae GraySubject 142 GrayPage 547 Image Gray492.png Caption Sternocostal surface of heart. Anterior descending branch labeled at upper right. Image2 Caption2 BranchFrom left coronary artery BranchTo septals, diagonals Vein Supplies anterolateral myocardium , apex, interventricular septum , 45 55 of the left ventricle LV MeshName MeshNumber DorlandsPre r 02 DorlandsSuf 12690388 The LAD , or left anterior descending artery or anterior interventricular branch of the left coronary artery , or anterior descending branch is an artery of the heart . Course It passes at first behind the pulmonary artery and then comes forward between that vessel and the left auricula to reach the anterior interventricular sulcus , along which it descends to the incisura apicis cordis . In 78 of cases, it reaches the apex of the heart . Supply It supplies the anterolateral myocardium , apex, and interventricular septum . The LAD typically supplies 45 55 of the left ventricle LV . Branches The LAD gives off two types of branches septals and diagonals . Septals originate from the LAD at 90 degrees to the surface of the heart, perforating and supplying the interventricular septum . Diagonals run along the surface of the heart and supply the lateral wall of the left ventricle and the anterolateral papillary muscle . The Widowmaker Because the LAD provides much of the bloodflow for the left ventricle, which in turn provides much of the propulsive force for ejecting oxygenated blood to systemic circulation via the Aorta blockage of this artery is particularly associated with mortality. In the medical community ischemic heart attacks associated with this blood vessel are colloquially called the widowmaker. Additional images File Coronary arteries.png thumb 300px left Coronary arteries labeled in red text and other major landmarks in blue text . Left anterior descending or interventricular artery is labeled ... more details
A myocardial bridge occurs when one of the Coronary circulation coronary arteries tunnels through the cardiac muscle myocardium rather than resting on top of it. Typically, the arteries rest on top of the heart muscle and feed blood down into smaller vessels that populate throughout the myocardium. But if the muscle grows around one of the larger arteries, then a myocardial bridge is formed. As the heart squeezes to pump blood, the muscle exerts pressure across the bridge and constricts the artery. This defect is present from birth. It can lead to uncomfortable, powerful heartbeats and angina. The incidence of the condition in the general population is estimated at 5 based on autopsy findings, ref name Pelliccia2009 citation last Pelliccia first Antonio year 2009 title Sports Cardiology Casebook publisher Springer isbn 9781848820418 page 141 ref but significance when found in association with other cardiac conditions is unknown. ref name Ragosta2009 citation last Ragosta first Michael year 2009 title Cardiac Catheterization An Atlas and DVD publisher Elsevier Health Sciences isbn 9781416039990 page 146 ref The condition is diagnosed on a scaled based on what percentage of obstruction occurs. If there is less than 50 blockage, then the condition is probably benign. A result of at least 70 usually causes some pain. Small amounts of myocardial bridging often are undetectable, as the blood usually flows through the coronary while the heart is relaxing in diastole . This condition can cause complications such as vasospasm , angina pectoris , arrhythmia , Vtach . Additionally many patients express discomfort in specific positions, i.e. lying on the left side for a prolonged period of time . Case study File Myocardial bridges.jpg thumb 330px Figure 1 Angiogram showing myocardial bridging resulting in arterial compression. Figure 1 shows a series of angiographic images with a bridge on the left anterior descending coronary artery LAD in a male patient of 65 years. A1 Right ... more details
are varied, and relate either to the actual inflammation of the myocardium, or the weakness ... granulocyte eosinophilic infiltrate involving the endocardium and myocardium H&E stain hematoxylin .... Many secondary causes, such as a heart attack, can lead to inflammation of the myocardium and therefore the diagnosis of myocarditis cannot be made by evidence of inflammation of the myocardium alone ... viruses known to affect the myocardium . Markers of myocardial damage troponin or creatine kinase ... in pericarditis . ref name Feldman The gold standard test gold standard is still biopsy of the myocardium, generally done in the setting of angiography . A small tissue sample of the endocardium and myocardium ... by visualizing markers for inflammation of the myocardium . ref cite journal author Skouri HN ... more details
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