Pathophysiology of cardiac arrhythmia pdf

Pathophysiology of cardiac arrhythmias automaticity reentry loops an impulse travels continuously around a circular re entrant path in the myocardium, continuously depolarizing that cardiac region. Vf is the most commonly identified arrhythmia in cardiac arrest patients. Basic cardiac rhythms identification and response utmc. Acls guidelines are also utilized in assisting the students in arrhythmia identi. Once initiated, arrhythmias can be sustained by the normal anatomical variations of cardiac structures. Cardiac or cardiovascular syncope is caused by various heart conditions, such as bradycardia, tachycardia or certain types of hypotension. Request pdf on feb, 2019, dhinakaran s and others published arrhythmias. Alternatively, the simple process of normal aging can adversely affect the hearts ability to maintain normal rhythms. The american heart association has information about atrial fibrillation, quivering heart, bradycardia, slow heart rate, premature contraction, tachycardia, fast beat, ventricular fibrillation, fluttering heart, rhythm disorders, treatment of arrhythmia, symptoms of arrhythmia, diagnosis of arrhythmia, monitoring the heart, and much more. Pharm, 3rd year, 6th semester netaji subhas chandra bose institute of pharmacy tatla, roypara, chakdaha, distnadia, pin 741222 affiliated to maulana abul kalam azad university of technology bf142, sector 1, saltlake city. The autonomic nervous system plays a key role in the development and progression of pah and right heart failure and has been implicated in pathogenesis of arrhythmia and sudden cardiac death scd. The aim of the present chapter was to provide a concise overview of available data regarding epidemiology and pathophysiology of ventricular arrhythmias in several noncardiac diseases, to mention the main methods used to assess arrhythmia risk, as well.

Vascular resistance increased due to reflex sympathetic outflow and reninangiotensin system though elevated afterload. Cardiac arrhythmias john a kastor,university of maryland, baltimore. The cardiac diseases that lead to the genesis of the arrhythmia resulting in cardiac collapse and sudden death are varied, and the association with sudden death in some cases is poorly understood. Arrhythmogenesis and types of arrhythmias as a pumping organ with an intrinsic electrical system, the. Define and employ the terms preload, afterload, contractilty, remodeling, diastolic dysfunction, compliance, stiffness and capacitance. Atrial pressure increased in heart failure due to increased blood volume and venous tone treated with salt restriction and diuretics afterload. Pathophysiology, incidence, management, and consequences. The term arrhythmia refers to any change from the normal sequence of electrical impulses.

Arrhythmia, variation from the normal rate or regularity of the heartbeat, usually resulting from irregularities within the conduction system of the heart. Arrhythmias may cause sudden death, syncope, heart failure, dizziness, palpitations or no symptoms at all. Arrhythmias occur in both normal and diseased hearts and have no medical significance in and of themselves, although they may endanger heart function when coupled with other cardiac. The expectation is that they will be able to identify the arrhythmia type on lead ii and learn the standard advanced cardiac life support acls treatment guidelines for this form of arrhythmia 7,12. Without an effective heartbeat, blood pressure plummets. This orderly progression of impulse formation and propagation ensures a synchronous sequence of contraction in atrial and ventricular myocardium. Arrhythmia etiology arrhythmia pathophysiology the. A large number of biochemical pathways are activated as a result of the cpa. Arrhythmia and conduction disturbances may be asymptomatic or cause palpitations sensation of skipped beats or rapid or forceful beats, symptoms of hemodynamic compromise eg, dyspnea, chest discomfort, presyncope, syncope, or cardiac arrest.

Antiarrhythmic drugs to maintain sinus rhythm in patients with atrial fibrillation. Request pdf pathophysiology of cardiac arrhythmias. Ventricular fibrillation is one type of arrhythmia that can be deadly. Pathophysiology of cardiac arrhythmias springerlink. However,manypatientswitharrhythmiasreportnosymptoms,andtheconditionmay. Defination cardiac arrhythmia is a condition in which the heart beats with an irregular or abnormal rhythm. The underlying mechanism for the origins of vf is poorly understood, but prolonged monomorphic vt is a known risk factor, contributed by ischaemia, free radical production, and intracellular. The pathophysiology of cardiac arrests is also now better understood. Ventricular arrhythmia risk in noncardiac diseases. Ventricular fibrillation vf is a lifethreatening, chaotic rhythm, with marked variability in cycle length and morphology up to 300 beats min. Seminar on cardiac arrhythmia and its treatment submitted by souvik pal roll no. An abnormality of the cardiac rhythm is called a cardiac arrhythmia. Ventricular arrhythmias and sudden cardiac death bja. Describe the normal cardiac anatomy and physiology and normal.

Classification, pathophysiology, and mechanisms of af. These result in the postcardiac arrest syndrome, which affects many systems in the body, but in particular the brain, heart, and kidneys. Arrhythmia pathophysiology and treatment pharmacotherapy 1. Other increased risks are of embolisation and stroke, heart failure and sudden cardiac death. It occurs when the heart beats with rapid, erratic electrical impulses.

Disruptions in the orderly pattern of this propagating cardiac excitation wave can lead to arrhythmias. Pathophysiology and causes of cardiac arrest oxford medicine. Blood circulation is the result of the beating of the heart, which provides the mechanical force to pump oxygenated blood to, and deoxygenated blood away from, the peripheral tissues. Abnormal impulse initiation results from either automaticity or triggered activity. Several schemes have been used to classify the mechanisms of cardiac arrhythmias. Almost two decades after the lancet s groundbreaking arrhythmia octet in 1993, cardiac electrophysiology has developed as a subspecialty so successfully that specialist cardiology units are now likely to have almost as many electricians as plumbers, according to andrew grace, who orchestrated the current series one recurring theme of the series is the successful application of. This causes pumping chambers in your heart the ventricles to quiver uselessly instead of pumping blood. Identification of the patient at risk for sudden death and identification of the factors that precipitate the fatal arrhythmia continue to represent. Arrhythmias result from abnormalities of impulse initiation or impulse conduction or a combination of both. Arrhythmia pathophysiology and treatment pharmacotherapy. Isbn 9789535112211, pdf isbn 9789535171911, published 20140212. Certain inherited congenital heart defects can cause abnormalities within the developing electrical system that can appear even before birth. Pharm pharmacy practice 1st sem faculty of pharmacy jamia hamdard 2. Once the diagnosis of tcmp has been made, many authors advocate a proactive treatment approach.

If an arrhythmia results in a heartbeat that is too fast, too slow or too weak to supply the bodys needs, this manifests as a lower blood pressure and may cause lightheadedness or dizziness, or syncope fainting. Cardiac arrhythmias mechanisms, pathophysiology, and treatment. The electrical impulses may happen too fast, too slowly, or erratically causing the heart to beat too fast, too slowly, or erratically. Arrhythmiaboth atrial and ventricularis a common comorbidity with hypertension ht. Clinical electrophysiology we have endeavored to relate known electrophysiologic mechanisms of arrhythmia development to clinically occurring arrhythmias, realizing that definitive conclusions can only be surmised at present. Reentry loops occur in branched, dysfunctionalfibrotic myocardium w. For clarity and simplicity of text, we will refer to the group 1 pah and group 4 cteph patients collectively as pahcteph, unless otherwise noted. Disturbances in cardiac rhythm are a result of abnormalities in impulse initiation, or conduction, or both.

Cardiac dysrhythmias pathophysiology and therapeutic. The genesis of cardiac arrhythmias is generally categorized into disorders of impulse formation, disorders of impulse conduction, or combinations of both. The teaching of the pathophysiology and pharmacological treatment of cardiac arrhythmias can be a challenging task. Occasionally, polyuria results from release of atrial natriuretic peptide during prolonged. Pathophysiologic mechanisms of cardiac arrhythmias. Normal cardiac rhythm occurs when spontaneous electrical impulses generated in the sinoatrial sa node are transmitted via the specialized conducting pathways to working myocardium. Ventricular fibrillation vf is a lifethreatening cardiac arrhythmia in which the coordinated contraction of the ventricular myocardium is replaced by highfrequency, disorganized excitation, resulting in the effective failure of the heart to pump blood. Heart failure mat maurer, md associate professor of clinical medicine objectives at the conclusion of this seminar, learners will be able to. People suspected of having cardiac syncope but who dont have serious medical conditions may. Cardiac arrhythmias mechanisms, pathophysiology, and. Volume 106 number 4, part 2 arrhythmia pathophysiology 809 tion in the cardiac syncytium in which they are measured 6 spach et al.

The cardiac action potential results from the sequential opening and. The exact strategy employed is dependent on the causative arrhythmia, as detailed below, where either a rate or rhythm control strategy may. Describe the electrical conduction system of the heart 3. Underlying mechanisms are many and various, including left ventricular hypertrophy lvh, myocardial ischemia, impaired left ventricular function and left atrial enlargement. Automaticity can further be subdivided into 1 automaticity caused by. Arrhythmia types in the next video well talk about arrhythmia medication, so. Pathophysiology of dr kamran afzal learning oje tives. Identify hemodynamic consequences of various rhythms 4. Overview of arrhythmias cardiovascular disorders msd.