5.11 Medication-Related ECG Changes Class IA Antiarrhythmics (E.g., Quinidine) ECG characteristics: Class IA: Quinidine, disopyramide, procainamide Mechanism of action: Blockade of the voltage-dependent sodium channels raising the threshold potential (phase…
3.10 Atrial Fibrillation Comparison of Isthmus-Dependent “Typical” Atrial Flutter (Counter-Clockwise vs. Clockwise) Atrial Fibrillation—In General Mechanism: Mostly left atrial micro-reentry with changing circuits of excitation Left atrial dilatation has a…
4.2 Stress-Induced Ischemia in Coronary Heart Disease Stress-Induced Ischemia in Coronary Heart Disease Mechanism: In the affected area the inner myocardial layer (endocardium) is particularly susceptible to ischemia (so-called last…
2.6 Further Explanations (I) Blockade of conduction arises between the sinus node and the atrium or in the region of the AV node (between the atrium and the ventricle). A…
3.9 “Typical” Atrial Flutter Nonisthmus-Dependent “Atypical” Atrial Flutter (Right Atrial With Atrial Septal Defect) Differential diagnosis: Typical atrial flutter Atrial ectopic tachycardia AV nodal reentry tachycardia Orthodromic WPW tachycardia Sinus…
3.5 Mixed Types of Block Left Posterior Hemiblock Differential diagnosis: Right bundle branch block Left bundle branch block Left anterior hemiblock Bifascicular block WPW syndrome Bifascicular Block—Complete Right Bundle Branch…
3.13 Ventricular Tachycardia Slow Monomorphic Ventricular Tachycardia Following Anterior Infarction, Spontaneous Termination Etiology: Coronary heart disease with status post infarct Mechanism: Area in the region of the infarction scar with…
3.12 Ventricular Extrasystole Ventricular Extrasystole—Singular Mechanism: Focal activity, interventricular reentry, or reentry around scars (infarct, patch, etc.) ECG characteristics: Premature widened QRS complex with compensatory pause (2 × RR) With…
5.1 Left Ventricular Hypertrophy Left Ventricular Hypertrophy Mechanism: Hypertrophy of the left ventricular musculature as a consequence of systolic or diastolic overload This determines: Rotation of the cardiac axis in…
5.12 ECG Changes With Electrolyte Shifts Digitalis Characteristics: Positive inotropic substance Mechanism of action: Blockade of sodium–potassium–ATPase, causing an increase in intracellular calcium Among other features, slowing of conduction at…
