…conductance shortens the atrial action potential duration (APD), hyperpolarizes the membrane potential, and decreases atrial contractility. Analogous electrophysiological changes occur within the sinus and atrioventricular…

…a normal or low pulse pressure, an elevated jugular venous pressure with a paradoxical rise on inspiration (Kussmaul sign), and a difficult to palpate apex…

…excellent, with the vast majority of patients recovering completely after restoration of sinus rhythm (or any other rhythm with normal ventricular rate and activation). Recovery…

…Sick sinus syndrome or symptomatic bradycardia in the absence of a pacemaker. Hypersensitivity to adenosine. Administration Normal route : Peripheral intravenous (IV). Alternative route : Central venous…

…accumulates in the pericardial space. Intrapericardial pressure may reach the point where the ventricles and atria can no longer relax normally, and the ventricles may…

…Management : : : Medial triangle of the face (nasal root, alae nasi, upper lip) Venous drainage towards the cavernous sinus Surgeon or ENT; often antibiotics Palm, fingers…

…occur in over 40% of females and 30% of males due to a lack of effective reflex response to posture, venous pooling, or external stimuli…

…etiologies when promptly and appropriately addressed. Both venous and arterial blood gases can be utilized for the analysis of electrolyte levels. Electrocardiography (ECG) serves as…

…the urinary tract. Marked bradycardia, sick sinus syndrome or high grade AV block without pacemaker protection. Asthma and other marked obstructive airways disease — relative; the…

…where the pads would go. Transvenous pacing: the relative contraindications are the same as for a central venous catheter — coagulopathy, infection at the puncture site…

…activity despite ongoing sinus rhythm on the ECG. Subacute rupture may be suggested by: Nausea. Hypotension. Pericardial or pleuritic discomfort. Syncope. Restlessness. Jugular venous distension…

…However, sinus arrhythmia may be a pathological finding in some cases. Sinus arrhythmia is not a normal finding among older individuals. In that scenario it…

…g during intense emotional stress) During vagal maneuvers (Valsalva maneuver, carotid sinus [baroreceptor] stimulation). It is common to discover SB in healthy young individuals who…

…Moreover, it is still debated whether the transient periods of atrial standstill in sinus bradycardia are associated with an increased risk of thromboembolism. Pacemaker treatment…

Arrhythmias and arrhythmology ECG Sinus rhythm: the normal rhythm of the heart A rhythm is defined as three consecutive heartbeats with identical waveforms on the…

…P wave is positive in lead II. Figure 1. ECG showing sinus tachycardia. Paper speed 25 mm/s. Calculate the heart rate by dividing 300…

…the sinus P wave, but the QRS complex is normal (provided that intraventricular conduction is normal). This rhythm may be referred to as atrial rhythm…

…12 \times \text{BSA} ) ≥40 years : ( \text{SOVd} = 1.92 + 0.74 \times \text{BSA} ) Definition of aortic aneurysm Sinus of Valsalva 45 mm…

CPR ECG 1 . Sinus rhythm interrupted by ventricular tachycardia (VT). ECG 2 . Spontaneous termination of ventricular tachycardia (VT). ECG 3 . A single ventricular beat, followed…

CPR ECG 1 . Sinus rhythm interrupted by polymorphic VT. ECG 2 . Polymorphic VT. ECG 3 . Polymorphic VT progresses to ventricular fibrillation (VF). ECG 4 . Polymorphic…

Referensvärden The normal values below apply to adults in sinus rhythm, recorded at a paper speed of 50 mm/s with 1 mV = 10…

…adjusted Aortic annulus 20 31 mm 12 14 mm/m2 Sinus valsalva 29 45 mm 15 20 mm/m2 Sinotubular junction 22 36 mm 13…

…should always be completed (regardless of whether conversion to sinus rhythm occurs) unless contraindications occur. If hemodynamically stable atrial flutter occurs after the first dose…

…the AVN and the conduction system occurs more often than sinus node involvement, and atrioventricular block (AVB) may indicate septal involvement in the inflammatory process…

…ECG diagnosis and management Atrial fibrillation is the most common abnormal tachyarrhythmia (only sinus tachycardia is more common). The prevalence of atrial fibrillation correlates strongly…

ECG Principles of myocardial excitability Myocardium is excitable not only by action potentials originating in the sinus node, but also by external electrical stimuli that…

…recorded simultaneously. Sex : Male Age : 43 years History : None Medications : None ECG 1 . Sinus rhythm interrupted by rapid ventricular tachycardia (VT). ECG 2 . VT progressing…

…Coronary bypass grafting; history of arrhythmias. Medications : beta blockers ECG 1 . Sinus rhythm interrupted by ventricular tachycardia (VT). ECG 3 . Ventricular fibrillation (VF). ECG 4…

…the atrial rate (beats/min)? P waves should precede every QRS complex and the P wave should be positive in lead II. Common findings Sinus…

…level, producing atrioventricular (AV) or intraventricular blocks. Isolated sinus bradycardia in the early hours following infarction may be associated with hemodynamic compromise. More broadly, bradyarrhythmic…

…action is exerted in the sinus node, it is effective only when the patient is in sinus rhythm. Its role in atrial fibrillation remains uncertain…

…wave in sinus rhythm. However, an ectopic focus may be located anywhere. If it is located near the atrioventricular node, activation of the atria will…

…quinidine ECG 1 . The initial beats are supraventricular beats during sinus rhythm. A brief run of polymorphic ventricular tachycardia (VT) occurs after the 4th beat…

…any arrhythmia arising in the atria may have wide QRS complexes if the ventricles cannot be depolarised normally (example: sinus tachycardia together with left bundle…

…Hypokalemia Hypomagnesemia Hypocalcemia Starvation Anorexia nervosa Liquid protein diets Hypothyroidism Bradyarrhythmia Sinus bradycardia Sinus node dysfunction AV blocks Drugs Drug Brands TdP Risk Class Clinical…

…de pointes . ECG showing an episode of sinus rhythm (with multiple ventricular premature beats) spontaneously converting to Torsade de Pointes ventricular tachycardia. Notice how arterial…

…the heart rate or a PVC induced pause. The subsequent sinus beat typically exhibits a longer QT interval, and the T wave is interrupted by…

Arrhythmias and arrhythmology Critical care Definition and pathophysiology Atrial fibrillation (AF) is the most frequent supraventricular arrhythmia in patients with acute coronary syndromes (ACS) and…

…congenital anomalies include anomalous origin of a coronary artery from the pulmonary artery and anomalous origin of one coronary artery from the opposite aortic sinus…

…receiving digoxin reveals specific electrophysiologic profiles. Digoxin's autonomic actions largely slow the sinus node discharge rate, shorten atrial refractoriness, and prolong AV nodal refractoriness…

…2nd AV block, prolonged QT interval, and profound sinus bradycardia are typically considered abnormal or profound findings that may require further investigation. 2. What heart…

…Electrophysiologically, the drug prolongs atrial and ventricular refractoriness, extends the A H and QT intervals, and increases sinus cycle length. Clinical Presentation and Symptoms The…

…atrial flutter, paroxysmal supraventricular tachycardia, and hemodynamically compromising ventricular tachycardia, while defibrillation (unsynchronized shock) is reserved for ventricular fibrillation, where urgent reversion to sinus rhythm…

…occur in one patient. The typical depiction of sudden cardiac death as a gradual transition from sinus rhythm to ventricular tachycardia (VT), to ventricular fibrillation…

…amiodarone or digitalis. Sinus node dysfunction (SND) is a common cause of chronotropic incompetence. Definition of chronotropic incompetence: the age expected maximal heart rate Chronotropic…

…which is synonymous with tachyarrhythmia. Except for sinus tachycardia during physical activity, all tachycardias should be considered pathological and the task is to clarify the…

…poorer than the prognosis for most cancers, whereas tachycardia induced cardiomyopathy can be cured completely by restoring sinus rhythm. Dilated cardiomyopathy is currently the most…

…threatening arrhythmias. Antiarrhythmic drugs Disopyramide Indications Prophylaxis and treatment of symptomatic ventricular tachyarrhythmias. Prophylaxis and treatment of atrial fibrillation. Effects of disopyramide on ECG, heart…

…segment elevation in leads V1–V2. All degrees of AV block. Sinus node dysfunction and tach brady syndrome. Ventricular tachycardia, ventricular fibrillation and torsade de…

…V3, which is normal in men and women. ECG example 7. Sinus rhythm. Relatively large T waves in V2 V3, with ST segment elevations. Relative…

…the atrial rate (beats/min)? P waves should precede every QRS complex and the P wave should be positive in lead II. Common findings Sinus…

…AV block. Sinus node dysfunction can be caused by supraventricular tachyarrhythmias (e.g. atrial fibrillation). Typically, periods of sinus node dysfunction occur after tachyarrhythmia; the…

…Principles of myocardial excitability and the conduction system Achieving an effective pumping mechanism requires the atria and the ventricles to be activated rapidly and sequentially…

…sinus rhythm . Parts of the atrial myocardium : There are clusters of atrial myocardial cells located around the crista terminalis , the entrance of the coronary sinus…

…airway disease. Contraindications also include second degree or third degree AV block, sinus node dysfunction without a pacemaker, systolic blood pressure below 90 mmHg, and…

…Thus, the P wave morphology of premature atrial beats differs from the sinus P wave. Note that the P wave might occur on the preceding…

…complexes are not preceded by P waves because the ectopic impulse originates in the ventricles and does not influence the atria (with exceptions discussed below)…

…disease may also lead to endocardial fibrosis. Rheumatic heart disease Sinus of Valsalva aneurysm : The aneurysm may compress the pulmonary outflow. Myxoma : Myxomas may compress…

…to the onset of atrial depolarization is prolonged. As seen in Figure 1 this merely entails that the distance between the sinus impulse and P…

…year old male. Each ECG presents two leads recorded simultaneously. ECG 1 . Sinus rhythm interrupted by ventricular fibrillation (VF). ECG 2 . Ventricular fibrillation. ECG 3…