The Curbsiders Internal Medicine Podcast

Episode #473: Rapid Response Series: Narrow Complex Tachyarrhythmias with Dr. Noble Maleque
Release Date: March 3, 2025

Episode Overview

In this high-yield rapid response episode, hosts Dr. Moni Amin and Dr. Meredith Trubitt are joined by hospitalist and educator Dr. Noble Maleque to break down the bedside management of acute narrow complex tachyarrhythmias. The discussion centers on practical approaches for hospitalists encountering rapid heart rhythms on inpatient wards, focusing on initial assessment, stabilization, and tailored therapeutic interventions. The conversation balances clinical decision-making, guideline-based management, and pragmatic bedside wisdom—with characteristic Curbsiders humor making complex cardiology topics approachable.

Key Discussion Points and Insights

1. Approaching the Rapid Heart Rate Call (08:11–15:25)

• First Steps:
  Dr. Maleque advises starting with two priority questions for the nurse:

  1. How is the patient doing clinically?
  2. What are the full vital signs?
     (08:11)

  "If they don't give you all the vitals, I think all vitals really are important… blood pressure to go along with the heart rate would be the first two things I would ask."
  — Dr. Noble Maleque (08:30)

• Access and Monitoring:
  Emphasizes prompt assessment of IV access (large-bore peripheral preferred over central or PICC for quick med delivery), and ensuring EKG/rhythm strip acquisition for rhythm analysis. (09:25)

• Stable vs. Unstable—Defining “Stability”:
  Clinical instability is framed by hypotension, tachypnea, hypoxemia, chest pain, heart failure symptoms, or altered mentation, but also considers the team’s comfort level. (11:18)

  "Stability is both about the patient and your comfort level as a provider at the bedside."
  — Dr. Noble Maleque (12:25)

• Escalation:
  If unstable, proceed directly down the ACLS shock pathway with urgent help—“Do not pass go, do not collect $200…” (15:25)

2. Narrow Complex Tachyarrhythmia: Recognition and Early Differentiation (18:27–27:20)

• Defining Narrow Complex Tachycardia:
  Rate >100 bpm (more worrisome >140); QRS <120ms (three small ECG boxes). (19:10–19:48)

• Is it Sinus Tach or Not?
  Key early branch: sinus tach (usually reactive, seek underlying cause) vs. other SVTs (AVNRT, AVRT)—though bedside recognition can be tough, even for EPs. (20:14–24:55)

  "I think the things that I'm looking for are P waves—are we seeing sinus tachycardia or not? That is one of the key things to figure out, which also can be really challenging."
  — Dr. Noble Maleque (20:35)

• Importance of Regularity:
  Is the rhythm regular or irregular? This helps narrow down likely tachyarrhythmia types (AFib, AFlutter, versus regular SVTs). (23:54)

• “Diagnosis and treatment are happening at the same time”:
  Assessment tools include rhythm change history, triggers, medication review, and how the arrhythmia started (gradual vs. sudden), in addition to physical and diagnostic maneuvers. (25:33–27:20)

3. Vagal Maneuvers: Updated Evidence & Bedside Pearls (27:20–32:38)

• Modified Valsalva is Best:
  Advocates the CHAMPIONED “modified Valsalva,” per 2015 RCT:

  1. Patient bears down (15 sec) while sitting, using a 10cc syringe to generate pressure.
  2. Immediately lie flat and raise both legs (leg lift).
     This method is ~2.5x more effective than classic Valsalva. (28:19–30:54)

  "In this particular study, that modified Valsalva was two and a half times more likely to lead to resolution of their tachyarrhythmia… I would recommend using the modified Valsalva."
  — Dr. Noble Maleque (29:55)

• Contraindications:
  Recent MI, severe aortic stenosis, high intracranial/intraocular pressure, or inability to lie flat/raise legs.

• Carotid Massage:
  Still in guidelines; check for bruits before attempting; likely less effective than Valsalva/modified Valsalva. (31:59–32:38)

• Can try both maneuvers while prepping meds if time allows. (32:55)

4. Adenosine and Acute Medical Therapy (33:30–39:31)

• Adenosine is First-Line in Stable Regular Narrow Complex Tachyarrhythmia:
  Rapid push, pads on, large-bore IV essential. Patient counseling is critical due to transient side effects (flushing, chest pain, "impending doom"). (33:56–37:14)

  "It's a really neat thing to do. It's scary as well… They can have all sorts of feelings, but it's so fleeting and transient that by the time they think about it, they're already getting better."
  — Dr. Noble Maleque (36:08)

• Dosing:
  6mg IV push x1, repeat with 12mg, then 12mg if needed (though often, help is called before third dose). (37:20–43:22)

• Information Value:
  Even if adenosine doesn’t terminate rhythm, it can unmask the underlying diagnosis.

  "If it doesn't break, you still get good information — you get to see the underlying rhythm."
  — Dr. Noble Maleque (36:54)

• Second-Line Agents (If adenosine contraindicated or fails):

  • Beta-blockers (e.g., metoprolol 5mg IV; repeat in 15–20 min)
  • Calcium channel blockers (e.g., diltiazem 0.25mg/kg IV)
    Note: Many practitioners empirically use 10mg diltiazem, an underdose by guideline standards, often due to comfort and BP concerns. (41:47–43:46)

5. Case Recap – Regular Narrow Complex Tachycardia (44:51)

• If vagal maneuvers and adenosine break the rhythm, you’ve accomplished both diagnosis and therapy.
• Always consider calling for assistance in your comfort zone—no shame in involving Cardiology early.

6. Irregular (e.g., AFib with RVR): Nuanced Management (44:55–58:53)

• Scenario:
  61-year-old with HFrEF, acute decompensated HF, found to have AFib with RVR. (45:55–46:01)

• Initial Approach:
  Confirm stability, as usual. If truly stable, have time for diagnostic reasoning (volume status, underlying causes, etc.).

• Choosing Rate Control:

  • AV nodal blockers:
    • Beta-blockers (metoprolol) preferred over non-dihydropyridine CCBs (e.g., diltiazem/verapamil) in reduced EF.
    • If decompensated HF or low BP, use these with great caution—or avoid. (48:18–51:38)
  • Amiodarone:
    • 150mg IV bolus over 10 minutes, then infusion for refractory/unstable or strictly HFrEF patients.
  • Digoxin:
    • Reasonable in specific settings (often overlooked, but can be useful). "It's in your toolkit." (55:19–55:47)

  "When you look at the guidelines, when people have decompensated heart failure, really neither the beta blocker or the calcium channel blocker are… things you should be using. That's why this particular case… may be complicated."
  — Dr. Noble Maleque (48:49)

• Oral vs. IV Options:
  In stable patients, oral metoprolol is reasonable; IV reserved for more urgent control.
  "If they're stable, you can do oral medications. There's no urgency to use IV… their BP tolerates it better than IV push."
  (53:35–55:18)

• Clinical Judgment:
  Always treat the patient, not just the number.

7. Anticoagulation and Rhythm Control Decisions (56:50–59:21)

• Anticoagulation:
  Not always first priority in acute setting—stabilization comes first. Decision for anticoagulation and/or cardioversion is individualized; team-based with Cardiology input and based on stroke risk scores and intended rhythm strategy.

  "Anticoagulation is for reducing stroke risk. If this is someone who is headed towards cardioversion… then I would be more prone to do anticoagulation… But in acute management, it's not the first thing that comes to mind."
  — Dr. Noble Maleque (57:15)

Notable Quotes & Memorable Moments

• "I'll just say it out loud: tachyarrhythmias make me nervous, and I think it's actually a good type of nervous. Take your own pulse as you walk to the room."
  — Dr. Noble Maleque (12:27, 59:27)

• "Diagnosis and treatment are happening at the same time."
  — Dr. Meredith Trubitt (27:15)

• (On comfort with adenosine)
  "By the time they start to feel it, they're already getting better."
  — Dr. Noble Maleque (36:13)

• "I took it to three cardiologists—the cardiology fellow, the CCU cardiologist, and then the electrophysiologist—and I got three different interpretations. Made me feel good about myself, honestly."
  — Dr. Noble Maleque (24:55)

• (On teamwork)
  "Having your nurses and staff give you some sense of what happened prior to them calling you… the story, the history, is really important."
  — Dr. Noble Maleque (25:51)

Key Timestamps for Important Segments

• 08:11 – First steps when paged: stabilization checklist & questions
• 11:18 – Defining "unstable"
• 14:12 – Algorithm for unstable vs. stable patients
• 19:10 – What is a narrow complex tachyarrhythmia? (definition)
• 20:35 – Diagnostic approach: Sinus tach vs. "non-sinus" SVT
• 28:19 – Modified Valsalva maneuver and evidence
• 31:59 – Carotid massage: technique & safety
• 33:56 – Adenosine: indications, dosing, patient counseling
• 45:55 – Case 2: AFib with RVR in decompensated HFrEF
• 51:38 – IV vs. oral AV nodal agents; using amiodarone
• 55:19 – Digoxin: old but not obsolete
• 56:50 – Anticoagulation considerations
• 59:27 – Take-home points and pearls

Take-Home Points from Dr. Noble Maleque (59:27–60:29)

• It's okay to be anxious—tachyarrhythmias are inherently stressful.
• Assess stability early and trust your clinical judgment and local resources.
• For narrow complex tachyarrhythmias:
  • Differentiate sinus tachycardia (seek cause) vs. SVT (vagal, adenosine, AV nodal blockers, etc.)
• Use modified Valsalva as first maneuver for stable SVT.
• If wide complex, treat as VT until proven otherwise—get help early.
• Anticoagulation and rhythm strategy decisions are individualized and often deferred to the ongoing team.

Resources & Recommendations

• Check out Curbsider’s episode #363 on atrial fibrillation for deeper outpatient, AFib management.
• Refer to the episode guide and show notes for visual EKG examples (since audio can't capture the rhythm strips).

Episode Tone and Style

This episode is rich with humor (“take your own pulse as you approach the tachycardic patient”), bedside practicality, and gentle reminders that even experts are sometimes uncertain at the monitor. The conversation is fast-paced, supportive, and loaded with actionable clinical pearls.

Summary written by [Curbsiders Summarizer AI], maintaining the warmth, candor, and clarity of the hosts and guest. For full CME details and additional links, visit [Curbsiders.com].