Dr. Usman's Cardiology Notes

𝗗𝗶𝗴𝗼𝘅𝗶𝗻 — 𝗔 𝗖𝗹𝗮𝘀𝘀𝗶𝗰 𝗗𝗿𝘂𝗴 𝘄𝗶𝘁𝗵 𝗮 𝗧𝗶𝗺𝗲𝗹𝗲𝘀𝘀 𝗠𝗲𝗰𝗵𝗮𝗻𝗶𝘀𝗺 Digoxin, one of the oldest cardiac drugs still in use today, continues to play a critical role in the management of heart failure and atrial fibrillation. Despite newer agents, digoxin remains unique because of its dual action — both inotropic and chronotropic. Let’s dive into its mechanism of action, step by step. --- 🔬 𝗠𝗼𝗹𝗲𝗰𝘂𝗹𝗮𝗿 𝗧𝗮𝗿𝗴𝗲𝘁: 𝗡𝗮⁺/𝗞⁺-𝗔𝗧𝗣𝗮𝘀𝗲 𝗜𝗻𝗵𝗶𝗯𝗶𝘁𝗶𝗼𝗻 At the core of digoxin’s mechanism lies its inhibition of the Na⁺/K⁺-ATPase pump, located on the cardiac cell membrane. Normally, this pump extrudes 3 Na⁺ ions out of the cell and brings in 2 K⁺ ions, maintaining the electrochemical gradient. Digoxin binds to the extracellular domain of this pump, inhibiting its activity. This causes intracellular Na⁺ concentration to rise. This simple change triggers a cascade of ionic effects that ultimately increase cardiac contractility. --- ⚙️ 𝗦𝘁𝗲𝗽-𝗯𝘆-𝗦𝘁𝗲...

The Silent Surge: How Micro-plastics Are Invading Our Bodies — What You Need to Know & How to Protect Yourself Key Concept: Explore how micro-plastics are finding their way into human tissues, the emerging health concerns, and practical steps you can take today to reduce exposure and safeguard your well-being. --- Introduction We live in a world surrounded by plastic — packaging, bottles, containers, even clothes with synthetic fibres. But what if tiny plastic fragments, invisible to the naked eye, are on the move: entering our bodies, circulating in our tissues, and quietly affecting our health? This is the emerging issue of micro-plastics: plastic particles smaller than 5 millimetres (and many much smaller) that are now showing up in oceans, soils, food chains — and according to recent studies — in human tissues too. For many people this topic still floats below the public radar, yet searches are rising, and the content online remains thin. This is a perfect opportunity for infor...

The Future of Heart Health: How AI is Detecting Heart Disease Before Symptoms Appear A New Era of Prevention in Cardiology For decades, heart disease has remained the leading cause of death worldwide — often striking silently until it’s too late. But a revolution is quietly taking place: Artificial Intelligence (AI) is learning to detect cardiovascular disease before it even shows symptoms. This breakthrough could transform how we prevent heart attacks, strokes, and sudden cardiac deaths — shifting medicine from reactive to predictive care. What Is AI-Driven Cardiac Screening? AI algorithms are trained on thousands (sometimes millions) of ECGs, echocardiograms, and cardiac MRI scans. These systems learn subtle patterns that even the most experienced clinicians might miss. For example: AI can detect asymptomatic left ventricular dysfunction on a standard ECG. It can predict future heart failure risk years in advance. Some models can even analyze your voice or facial blood flow patterns ...

  Hidden Therapies: How Drug Repurposing Could Revolutionize Treatment of Rare Diseases Key Concept: Discover how existing medications are being repurposed to treat rare diseases, bridging the treatment gap and bringing new hope to millions worldwide. Learn how this overlooked field could reshape modern medicine. --- Introduction: A New Hope for Rare Diseases Imagine hearing that your condition has no approved treatment. For millions of people living with rare diseases, that phrase is heartbreakingly familiar. There are over 7,000 rare diseases known today — but only a small fraction have any effective therapy available. While pharmaceutical innovation races ahead for common illnesses, patients with rare conditions are often left behind. But now, a powerful idea is transforming that outlook: drug repurposing — finding new uses for existing drugs. Instead of waiting years for a new compound to be discovered, what if we could use a medicine already sitting on the pharmacy shelf? This...

Closed Loop Stimulation (CLS) is an advanced pacing algorithm used in modern pacemakers — particularly by Biotronik — that allows the device to continuously adapt the heart rate according to the patient’s physiological needs, not just activity level. Here’s a breakdown 👇 --- 🔹 Concept Traditional rate-responsive pacemakers use sensors like: Accelerometers (detect body motion) Minute ventilation sensors (detect breathing rate) However, these only respond to external activity, not to emotional stress or internal changes (like pain, anxiety, or standing up suddenly). CLS, on the other hand, creates a closed feedback loop between the heart’s own signals and the pacemaker’s pacing rate. --- 🔹 How It Works 1. Sensing intracardiac impedance: The pacemaker continuously measures right ventricular impedance during each heartbeat. This impedance reflects myocardial contractility — which changes with autonomic nervous system activity (sympathetic and parasympathetic tone). 2. Interpreting contr...

  Approach to Narrow Complex Tachycardia (NCT) Narrow Complex Tachycardia (NCT) refers to any tachyarrhythmia (heart rate >100 bpm) with a QRS duration <120 ms on the ECG. It indicates that ventricular activation is occurring via the normal His–Purkinje system, meaning the origin of the rhythm is at or above the AV node. A systematic approach helps identify the underlying mechanism, guide acute management, and prevent recurrence. 1️⃣ Step 1: Confirm It’s a Narrow Complex Tachycardia Before labeling it NCT: QRS <120 ms (3 small boxes) — confirms supraventricular origin. Regular vs. Irregular rhythm — key to differential diagnosis. Rate — often 150–250 bpm for re-entrant tachycardias; <150 for sinus tachycardia or atrial flutter with block. Also exclude: Artifact or sinus tachycardia due to secondary causes (fever, anxiety, hypovolemia, thyrotoxicosis, etc.). --- 2️⃣ Step 2: Classify by Rhythm Regularity A. Regular Narrow Complex Tachycardia Possible causes: Sinus tachyca...

Here’s a simple, step-by-step guide to measuring Left Atrial Volume Index (LAVi) on echocardiography — clear enough for practical use and quick reporting 👇 --- 🧭 Key Concept LAVi = Left atrial volume (mL) ÷ Body Surface Area (BSA, m²) → Reported as mL/m² Normal ≤ 34 mL/m² --- 🩺 Step-by-Step: How to Measure LAVi 1. Acquire the right views Use apical 4-chamber (A4C) and apical 2-chamber (A2C) views. Ensure: LA is not foreshortened (true apex visible) LV long axis is fully elongated Endocardial borders are clearly seen --- 2. Select timing Measure at end-systole (when LA is largest) → Just before mitral valve opening --- 3. Trace the LA area Trace inner border of LA (exclude: pulmonary veins LA appendage mitral annulus thickness) Do it in both A4C and A2C. --- 4. Measure the LA length Measure longest perpendicular line from mid-mitral annulus to superior wall (shorter of A4C/A2C). --- 5. Calculate LA Volume (Biplane Simpson / Area–Length method) Biplane Method of Disks (Simpson’s): use...

To the point guide to check Pulmonary Hypertension (PH) / estimate PASP on Echo and how to report it 👇 🩺 Key Steps to Estimate Pulmonary Artery Systolic Pressure (PASP) 1. Get TR Jet (Tricuspid Regurgitation) Velocity Use apical 4-chamber or RV inflow view. Apply continuous-wave Doppler through TR jet. Optimize alignment with jet for peak TR velocity (V) in m/s. 2. Apply Bernoulli Equation Pressure gradient (ΔP) = 4 × (V)² → e.g. if TR velocity = 3.2 m/s → ΔP = 4 × (3.2)² = 41 mmHg 3. Estimate Right Atrial Pressure (RAP) Use IVC size and collapse on subcostal view: IVC < 2.1 cm and collapses > 50% → RAP = 3 mmHg IVC > 2.1 cm and collapses < 50% → RAP = 15 mmHg Intermediate → RAP = 8 mmHg 4. Calculate PASP PASP = 4(V²) + RAP --- 📊 Interpretation (Adults) PASP (mmHg) Interpretation < 30 Normal 30–40 Mild PH 41–55 Moderate PH > 55 Severe PH (Assuming no pulmonic stenosis or RVOT obstruction.) --- 🧾 Reporting Template Findings: Peak TR velocity: ___ m/s Estimated RV-R...

Cardiac Arrest and the ACLS Algorithm: A Complete Guide Cardiac arrest remains one of the most critical emergencies encountered in healthcare. It is the sudden cessation of effective cardiac mechanical activity, leading to loss of circulation and, if not promptly treated, death. Advanced Cardiac Life Support (ACLS) provides a structured, evidence-based approach to resuscitation, improving the chances of return of spontaneous circulation (ROSC) and survival with good neurological outcomes. Understanding Cardiac Arrest Cardiac arrest occurs when the heart stops pumping blood effectively. The underlying rhythm may be shockable or non-shockable: Shockable rhythms: Ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) Non-shockable rhythms: Asystole and pulseless electrical activity (PEA) Recognizing the rhythm type early is essential, as it determines the immediate steps in the ACLS algorithm. --- The ACLS Cardiac Arrest Algorithm (Step-by-Step) 1. Immediate Response If...

Myocardial Performance Index (Tei Index) – An Interesting One  The Tei Index, introduced by Dr. Chuwa Tei, is a Doppler-derived, noninvasive parameter that evaluates global ventricular performance, integrating both systolic and diastolic functions into a single measure. How It’s Measured: ⬜ Acquired using pulsed and continuous wave Doppler from: • Mitral inflow (Apical 4-Chamber view) • Left ventricular outflow (Apical 5-Chamber view) ⬜ Key intervals measured: a. IVCT – Isovolumetric Contraction Time b. IVRT – Isovolumetric Relaxation Time c. ET – Ejection Time Formula: 👉 Tei Index = (IVCT + IVRT) / ET or 👉 Tei Index = (a - b) / b where: a = time from mitral valve closure to opening b = aortic ejection time Normal Values: LV Tei Index: ≤ 0.40 RV Tei Index: ≤ 0.43 Interpretation: 🔵 Higher Tei Index → Impaired ventricular function 🔵 Detects early ventricular dysfunction, even when LVEF appears normal Clinical Significance: Useful in assessing cardiomyopathies, heart failure, cong...

 Why You Should Avoid Processed Oils and Packaged Foods: The Hidden Truth About Additives and Their Effects In today’s fast-paced world, convenience often wins over caution. Packaged snacks, ready-to-eat meals, and refined cooking oils have become household staples. But behind the shiny labels and tempting flavors lies a complex web of chemical additives, industrial processing, and nutritional compromises that can harm our health in the long run. This article dives deep into why avoiding processed oils and packaged foods is one of the best choices you can make for your long-term well-being — and how the additives inside these products affect your body in ways you might not even realize. --- 1. The Rise of Processed Oils: From Natural Seeds to Industrial Liquids Once upon a time, oil was made by simply pressing olives, coconuts, or sesame seeds. Today, most cooking oils are the result of heavy industrial refining. Common processed oils include: Canola oil (rapeseed oil) Soybean oil ...

Left Ventricular Hypertrophy (LVH) is a common finding in patients with long-standing hypertension, aortic stenosis, or other conditions that increase left ventricular workload. Detecting LVH on an electrocardiogram (ECG) is crucial for identifying cardiac remodeling before structural heart disease becomes advanced. Although echocardiography remains the gold standard, ECG provides a fast and cost-effective screening tool. --- What is LVH? LVH refers to thickening of the left ventricular wall due to chronic pressure overload. On ECG, this manifests as increased QRS voltage and often secondary repolarization (strain) changes in the lateral leads. --- Main ECG Criteria for LVH 1. Sokolow–Lyon Criteria One of the oldest and simplest ECG criteria for LVH, mainly based on precordial lead voltages. Formula: S in V1 + R in V5 or V6 ≥ 35 mm (3.5 mV) (Use the larger R wave between V5 and V6) Optional additional criterion: R in aVL ≥ 11 mm Key Features: Easy and quick to apply. Best used in young...

Atrial Fibrillation Why AFib matters — beyond the heartbeat AFib is the most common sustained cardiac arrhythmia.  It is more than “just an irregular heartbeat”: it carries significant risks, including stroke, heart failure, reduced quality of life, and mortality.  Many people may not even know they have it — sometimes no symptoms, silent disease.  As the global population ages and cardiovascular risk factors (hypertension, diabetes, obesity) rise, AFib’s prevalence is increasing.  For clinicians: early detection, appropriate anticoagulation, rhythm/rate control, and lifestyle modification are critical. --- What happens in the heart (in plain language) Imagine your heart’s upper chambers (the atria) as concert halls where signals should arrive in perfect rhythm. In AFib: The atria don’t contract in a coordinated fashion; instead they “quiver” (fibrillate).  Many rapid, chaotic signals bombard the atrioventricular (AV) node and ventricles, so the heartbeat become...

Heart Failure: The Cardiology Topic Clinicians Search Most Heart failure (HF) emerges as the single most searched cardiology topic globally. It is a “rapidly growing public health issue” affecting an estimated 64 million people worldwide. In fact, heart failure is now a leading cause of hospitalization and mortality. Clinicians and researchers alike are focused on HF because its prevalence is rising (due to aging populations and better survival after heart attacks) even as outcomes remain poor. This immense burden – high mortality, frequent readmissions and poor quality of life – makes heart failure a central concern in cardiology. Online search trends reflect this intensity: Google query volumes for “heart failure” closely mirror the condition’s real-world prevalence. In short, heart failure is an ever-present topic in cardiology practice and research, and clinicians worldwide continually seek information on its diagnosis and management. Understanding Heart Failure Heart failure...

  C-peptide and antibody tests help distinguish between Type 1 diabetes, LADA, and MODY by assessing beta-cell function and autoimmune activity. Low C-peptide with positive antibodies indicates autoimmune Type 1 or LADA, while preserved C-peptide with negative antibodies suggests MODY or Type 2. This diagnostic approach guides appropriate therapy and avoids unnecessary lifelong insulin use. C-Peptide and Antibody Testing for Type 1 Diabetes, LADA, and MODY Understanding the role of C-peptide and antibody testing is essential for distinguishing between different types of diabetes, especially when clinical features overlap. These tests help confirm autoimmune diabetes, differentiate LADA (Latent Autoimmune Diabetes in Adults) from type 2, and identify patients who may have monogenic diabetes (MODY). --- What Is C-Peptide and Why It Matters C-peptide is produced in equal amounts with insulin when proinsulin splits into insulin and C-peptide. Measuring C-peptide tells us how much endog...