Dr. Usman's Cardiology Notes

Bartter, Liddle, and Conn Syndromes A practical comparison of salt-handling disorders causing metabolic alkalosis Disorders of renal sodium handling are frequently tested and clinically relevant because they present with characteristic patterns of blood pressure, electrolytes, and hormonal changes. Bartter syndrome, Liddle syndrome, and Conn syndrome all cause metabolic alkalosis but differ fundamentally in their mechanisms and clinical profiles. --- Bartter Syndrome Salt-wasting disorder mimicking chronic loop diuretic use Bartter syndrome is a hereditary defect of ion transport in the thick ascending limb of the loop of Henle, most commonly involving the Na–K–2Cl cotransporter (NKCC2) or related channels. Pathophysiology Impaired sodium reabsorption in the loop of Henle Renal sodium loss → extracellular volume depletion Secondary activation of RAAS Increased distal sodium delivery → potassium and hydrogen ion loss Key Biochemical Changes Increased Renin Aldosterone Decreased Sodium B...

  Characteristics of Cardiac Tumors Cardiac tumors are rare but clinically significant masses involving the heart. They may be primary (originating in the heart) or secondary (metastatic), and their presentation depends on size, location, mobility, and histology rather than malignancy alone. --- 1. Classification of Cardiac Tumors A. Primary Cardiac Tumors Very rare (incidence ~0.001–0.03%) ~75% are benign ~25% are malignant B. Secondary (Metastatic) Cardiac Tumors 20–40 times more common than primary tumors Common primaries: lung, breast, melanoma, lymphoma, leukemia --- 2. Benign Cardiac Tumors – Key Characteristics General Features Slow-growing Symptoms mainly due to obstruction, embolization, or arrhythmia Often curable with surgical excision Common Types Myxoma Most common primary cardiac tumor in adults Usually arises from left atrium (interatrial septum) Mobile, pedunculated May cause positional dyspnea, syncope, or embolic stroke Papillary fibroelastoma Small, highly mobile...

Coronary Artery Territories in the 17-Segment Echocardiography Model The 17-segment left ventricular (LV) model, standardized by the American Heart Association, is the cornerstone for regional wall motion analysis on echocardiography. Mapping each segment to its usual coronary artery supply helps localize ischemia and infarction accurately. --- The 17-Segment LV Model: Overview The LV is divided into 3 levels + apex: Basal level (6 segments) Mid-cavity level (6 segments) Apical level (4 segments) True apex (1 segment) Segments are named by level + wall (e.g., basal inferior, mid anteroseptal). --- Coronary Artery Territories 1. Left Anterior Descending (LAD) Artery Supplies the anterior wall, septum, and apex. Segments typically supplied by LAD Basal anterior Basal anteroseptal Mid anterior Mid anteroseptal Apical anterior Apical septal Apical cap (segment 17) Clinical correlation LAD ischemia → anterior/septal wall motion abnormality Proximal LAD occlusion → extensive dysfunction incl...

  Summary of the key 2025 ESC (European Society of Cardiology) guideline concepts on anticoagulation in atrial fibrillation (AF) as reflected in the latest evidence and updates presented around ESC Congress 2025 and implemented into the evolving clinical practice recommendations. Note: ESC’s most recent full official document for AF management is the 2024 guideline, and updates presented at ESC 2025 (including updates on anticoagulation after ablation) are incorporated as emerging guidance.  1) Stroke Risk Assessment & Indications for Anticoagulation • Patients with AF should have stroke risk evaluated using validated scores such as CHA₂DS₂-VASc (or the simplified CHA₂DS₂-VA) to guide anticoagulation decisions. A higher score signifies higher annual stroke risk and stronger indication for oral anticoagulants (OACs).  • Oral anticoagulation is recommended for patients with elevated thromboembolic risk — typically CHA₂DS₂-VA ≥2 or CHA₂DS₂-VASc ≥2 in most patients — to p...

  ATRIAL VS VENTRICULAR SECONDARY MITRAL REGURGITATION Mechanisms, Echocardiographic Features, and Clinical Implications INTRODUCTION Secondary (functional) mitral regurgitation (SMR) occurs due to distortion of left heart geometry rather than primary mitral valve leaflet disease. Traditionally linked to left ventricular (LV) dysfunction, it is now clear that a distinct entity—atrial secondary mitral regurgitation (ASMR)—exists, driven predominantly by left atrial (LA) and mitral annular remodeling. Differentiating atrial from ventricular SMR is essential because mechanisms, prognosis, and management strategies differ significantly. --- 1. DEFINITIONS Atrial Secondary Mitral Regurgitation (ASMR) Mitral regurgitation caused by left atrial enlargement and mitral annular dilatation, with preserved or near-normal LV systolic function and minimal leaflet tethering. Ventricular Secondary Mitral Regurgitation (VSMR) Mitral regurgitation resulting from left ventricular dilatation and dysfu...

Extracardiac uses of ranolazine 1. Neuropathic pain Blocks late Na⁺ current in neurons Reduces neuronal hyperexcitability Studied in diabetic neuropathy and chronic pain syndromes 2. Myotonia (off-label) Decreases skeletal muscle membrane excitability Helpful in myotonic disorders when mexiletine is not tolerated 3. Skeletal muscle cramps Reduces repetitive muscle fiber firing Anecdotal benefit in chronic painful cramps 4. Glycemic control (metabolic effect) Improves insulin sensitivity Lowers HbA1c in patients with diabetes (observed in trials) Mechanism: altered cellular Na⁺/Ca²⁺ handling and metabolism 5. Pulmonary hypertension (investigational) Improves right ventricular diastolic function May reduce pulmonary vascular remodeling via Na⁺/Ca²⁺ modulation 6. Neuroprotection (experimental) Late Na⁺ current inhibition may reduce neuronal calcium overload Studied in ischemia-related neuronal injury (preclinical data) Key concept Ranolazine’s late sodium current (INa-late) inhibition exp...

Conditions in which you should give anticoagulation in AF regardless of CHA₂DS₂-VASc score 1. Hypertrophic cardiomyopathy (HCM) 2. Fontan circulation 3. Systemic right ventricle 4. Intracardiac repair in congenital heart disease 5. Cyanotic heart disease 6. After AF ablation – minimum 8 weeks 7. After cardioversion – minimum 4 weeks 8. Mechanical prosthetic heart valve 9. Moderate or severe mitral stenosis 10. Anticoagulation for other indications   • Deep vein thrombosis (DVT)   • Pulmonary embolism (PE)   • Left ventricular thrombus 11. Thyrotoxicosis (reported in some studies) 12. Cardiac amyloidosis For more infographics: drmusmanjaved.com