Dr. Usman's Cardiology Notes

PVC Localization on ECG: Lets start with this ECG Case: Premature ventricular contractions (PVCs) are common arrhythmias often seen on routine ECGs or Holter monitors. While isolated PVCs are frequently benign, identifying their site of origin can be clinically important—especially in patients with symptoms, frequent ectopy, or underlying structural heart disease. ECG morphology offers valuable clues to help localize the origin of these ectopic beats within the ventricles. Basic Principles: PVCs originate from a single focus in the ventricular myocardium. Because of this, the activation spreads outside the normal conduction system, creating wide and bizarre QRS complexes. The QRS morphology and axis during a PVC provide hints about where in the ventricles the beat originates. Key Clues to Localization: 1. Outflow Tract PVCs (RVOT/LVOT) Most common type in structurally normal hearts. LBBB pattern in V1 (dominant S wave). Inferior axis (positive QRS in II, III, aVF) — indicating superior...

 Atrioventricular Septal Defect AVSD on echocardiogram stands for Atrioventricular Septal Defect, also known as atrioventricular canal defect or endocardial cushion defect. It is a congenital (present at birth) heart defect that involves abnormal development of the central part of the heart where the atrial and ventricular septa meet and where the tricuspid and mitral valves form. --- 💡 Key Echocardiographic Features of AVSD: There are three main types of AVSD seen on echocardiogram: 1. Complete AVSD Single common AV valve (instead of separate mitral and tricuspid valves). Large defect in the atrial septum (ostium primum ASD). Large defect in the ventricular septum (inlet VSD). Commonly seen in Down syndrome. 2. Partial (or Incomplete) AVSD Ostium primum ASD present. No VSD. Two separate AV valves, but the mitral valve is cleft, causing mitral regurgitation. 3. Transitional (or Intermediate) AVSD Like partial AVSD but with a small VSD beneath the common valve. --- 🫀 On Echocardio...

 Atrial Septal Defect (ASD) Device Closure: A Comprehensive Overview Case Presentation: A 25-year-old female patient presented with complaints of shortness of breath on exertion and palpitations for the past 6 months. She had no significant past medical history and was not taking any medications. Physical Examination: - Vital signs: Blood pressure 120/80 mmHg, pulse rate 90 beats per minute, oxygen saturation 98% on room air. - Cardiovascular examination: Revealed a systolic ejection murmur at the left upper sternal border, with fixed splitting of the second heart sound. - Chest examination: Clear lungs, no peripheral edema. Diagnostic Tests: - Electrocardiogram (ECG): Showed sinus rhythm with right axis deviation and incomplete right bundle branch block. - Chest X-ray: Revealed cardiomegaly with increased pulmonary vascular markings. - Transthoracic echocardiogram (TTE): Demonstrated a secundum atrial septal defect (ASD) with left-to-right shunting, right ventricular enlargement, ...

  ECG Interpretation The electrocardiogram (ECG) is a crucial diagnostic tool for assessing the electrical activity of the heart. A thorough understanding of ECG interpretation is essential for identifying various cardiac conditions and guiding clinical decision-making. Normal ECG A normal ECG consists of several key components: - P wave: represents atrial depolarization - PR interval: time between the onset of the P wave and the QRS complex - QRS complex: represents ventricular depolarization - QT interval: time between the onset of the QRS complex and the end of the T wave - T wave: represents ventricular repolarization Heart Rate To calculate the heart rate, count the number of R-R intervals in 6 seconds and multiply by 10. A normal heart rate is between 60-100 beats per minute. Rhythm Assess the rhythm by evaluating the P-P interval and R-R interval. A regular rhythm has a consistent P-P and R-R interval. P Wave Evaluate the P wave for morphology, duration, and axis. Abnormalit...

 Mitral Fibrous Ring Causing Mitral Stenosis Mitral annular calcification (MAC) or mitral fibrous ring can cause mitral stenosis, particularly in elderly patients. The calcification or fibrosis of the mitral annulus can extend to the leaflets, causing restricted mobility and stenosis. Causes - Degenerative changes - Aging - Hypertension - Atherosclerosis - Chronic kidney disease Echo Findings - Mitral annular calcification or fibrosis on 2D echo - Restricted mobility of the mitral leaflets - Reduced mitral valve area - Increased transmitral gradient - Doppler echo can estimate the mitral valve area and gradient Severity Assessment - Mild MAC: small, localized calcification - Moderate MAC: larger calcification with restricted leaflet mobility - Severe MAC: extensive calcification with significant leaflet immobility and stenosis Clinical Implications - Mitral stenosis can lead to symptoms like dyspnea, fatigue, and palpitations - Severe MAC can increase the risk of cardiovascular eve...

 During an electrophysiology (EP) study for typical AVNRT (Atrioventricular Nodal Reentrant Tachycardia), a VAV (Ventriculo-Atrial-Ventricular) response can be a crucial diagnostic finding. What is a VAV response? A VAV response occurs when a ventricular extrastimulus (a premature ventricular beat) is introduced during the tachycardia. This extrastimulus conducts retrogradely (backward) to the atrium, causing atrial activation (A). Subsequently, the atrium activates the ventricle again through the AV node, resulting in another ventricular activation (V). Why is the VAV response important in AVNRT? The VAV response helps diagnose AVNRT and differentiate it from other supraventricular tachycardias. In AVNRT, the VAV response typically demonstrates: 1. Retrograde conduction: The ventricular extrastimulus conducts backward to the atrium, indicating the presence of a retrograde pathway (usually the fast pathway). 2. Anterograde conduction: The subsequent atrial activation conducts down ...

    Infection Prevention & Control Assessment   Total MCQs = 30   Key is given at the end.   1.   What is the primary objective of environmental cleaning in healthcare settings according to WHO?         A. To maintain a pleasant smell in patient areas          B. To meet hospital accreditation standards         C. To remove dirt and reduce the presence of microorganisms         D. To reduce laundry workload   2.   Which of the following surfaces requires the most frequent cleaning?         A. Walls         B. Bed rails         C. Ceilings         D. Windows   3.   According to WHO guidelines, how often should high-touch surfa...