Cardiac disease

Can syncope be related to acute pulmonary embolism in the absence of hemodynamic instability or right ventricular failure?

FA Manian MD, MPH, , , , , , , , , Leave a comment

Although we often think of syncope caused by acute pulmonary embolism (APE) in the setting of submassive or massive APE and right ventricular failure or shock (1,2), less massive APE may potentially cause syncope as well by triggering a vaso-vagal reflex (3).

For sure, a significant association between submassive or massive APE and syncope has been reported (1,2).  More specifically, patients with syncope and APE may be more likely to have systolic blood pressure <90 mmHg, right ventricular dilation and right ventricular hypokinesis (1). Another study reported a higher rate of central embolism (83% vs 43%), right ventricular dysfunction (91% vs 68%) and troponin positivity (80% vs 39%), but not 30 day mortality (2).

In contrast, 1 study found that patients with syncope as a presenting symptom of APE did not show a more serious clinical picture (e.g. shock) than those without syncope (3), while another found EKG signs of acute right ventricle overload in only 25% of patients with syncope (4).  

So while massive APEs may be associated with syncope, they don’t seem to be a prerequisite for this condition.

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References

1.  Omar HR, Mirsaeidi M, Weinstock MB, et al. Syncope on presentation is a surrogate for submassive and massive acute pulmonary embolism. Am J Emerg Med 2018;36:297-300. https://www.ncbi.nlm.nih.gov/pubmed/29146419

2. Altinsoy B, Erboy F, Tanriverdi H, et al. Syncope as a presentation of acute pulmonary embolism. Ther Clin Risk Manag 2016;12:1023-28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4930221/

3. Castelli R, Tarsia P, Tantardini G et al. Syncope in patients with pulmonary embolism: comparison between patients with syncope as the presenting symptom of pulmonary embolism and patients with pulmonary embolism without syncope. Vascular Medicine 2003;8:257-261. https://journals.sagepub.com/doi/abs/10.1191/1358863x03vm510oa

4. Miniati M, Cenci, Monti S, et al. Clinical presentation of acute pulmonary embolism: survey of 800 cases. PloS One 2012;7:e30891.

 

 

Can syncope be related to acute pulmonary embolism in the absence of hemodynamic instability or right ventricular failure?

Does marijuana use lead to any adverse cardiovascular effects?

FA Manian MD, MPH, , , , , Leave a comment

Although marijuana is often not considered to have serious cardiovascular effects, in animal studies THC, the active ingredient in cannabis, has been found to affect cardiovascular activity through a number of mechanisms, including inhibition of adrenal catecholamine secretion and modulation of cardiac vagal tone through inhibition of norepinephrine release from sympathetic neurons (1).

There have also been reports of temporal association between marijuana use and acute coronary syndrome, cardiac arrhythmias, cerebrovascular events, including TIA’s, strokes, and cerebral vasospasm, as well as peripheral vascular events, including arteritis, Raynaud’s phenomenon, and digital necrosis (2).

In a recent comprehensive case series, about 2.0 % of all cannabis-associated adverse events were reported cardiovascular in nature, with 25% resulting in death (2). However, it is often difficult to determine the relative contribution of marijuana and other concurrent conditions or substances (e.g. alcohol and tobacco) when cardiovascular complications occur. More research in this area is needed.

References

1. Szabo B, Nordheim U, Niederhoffer N. Effects of cannabinoids on sympathetic and parasympathetic neuroeffector transmission in the rabbit heart. J Pharmacol ExpTher 2001; 297:819-826. http://jpet.aspetjournals.org/content/297/2/819

2. Jouanjus E, Lapeyre-Mestre M, Micallef J, et al. Cannabis use: signal of increasing risk of serious cardiovascular disorders. J Am Heart Assoc 2014; 3:e000638.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4187498/

Contributed by Pierre Ankomah, MD, Boston, MA

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Does marijuana use lead to any adverse cardiovascular effects?

Is central sleep apnea-Cheyne-Stokes respirations (CSA-CSR) in the setting of heart failure (HF) detrimental?

FA Manian MD, MPH, , , Leave a comment

CSA-CSR is characterized by a crescendo-decrescendo pattern of 20-30 second hyperventilation followed by 10- 40 second hypopneas or apneas during exercise, wakefulness or stages 1 and 2 non-rapid eye movement sleep (1,2).

CSA-CSR is associated with elevated pulmonary capillary wedge pressure, ventricular dilatation, atrial fibrillation, and increased central and peripheral chemosensitivity to arterial C02 levels (1).

In contrast to obstructive sleep apnea whose detrimental impact is widely accepted, CSA-CSA has not consistently been shown to be associated with higher mortality rates.  Some even argue that it may be beneficial in HF by providing intrinsic positive end-expiratory pressure (PEEP), augmented stroke volume, avoidance of hypercapnic acidosis, attenuated sympathetic activity, bronchodilation and cyclic respiratory muscle rest, akin to those seen with episodic CPAP (2).

Wow! Is CSA-CSR nature’s CPAP? This is an interesting way of looking at CSA-CSR, and underscores the importance of addressing the underlying problem (e.g. HF) rather than the symptoms alone.

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References

1. Rosen D, Roux FJ, Shah N. Sleep and breathing in congestive heart failure. Clin Chest Med 2014, 35: 521–534. https://www.ncbi.nlm.nih.gov/pubmed/25156768

2. Naughton MT. Cheyne-Stokes respiration: friend or foe. Thorax 2012;67:357-360. http://thorax.bmj.com/content/thoraxjnl/67/4/357.full.pdf

Is central sleep apnea-Cheyne-Stokes respirations (CSA-CSR) in the setting of heart failure (HF) detrimental?

Is the QTc interval an accurate reflection of myocardial repolarization time in ventricular conduction defects associated with a widened QRS complex?

FA Manian MD, MPH, , Leave a comment

Ventricular conduction defects associated with a widened QRS complex—specifically, complete and incomplete bundle branch blocks—may artificially elongate the QT interval without reflecting an actual increase in myocardial repolarization time (1).

In complete bundle branch block, the widened QRS complex may elongate the QTc interval by as much as 16% while having no effect on the JT index, defined as JT interval x (heart rate+ 100)/518), where an index >112ms is considered to be prolonged (2).

Calculation of the JT index has been suggested for patients with incomplete bundle branch block, as well (2).

Put simply, in patients with ventricular conduction defects associated with a widened QRS complex, the JT index appears to be superior to the QTc interval for assessment of repolarization time.

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 References

 

1. Salik J, Muskin P. Consideration of the JT interval rather than the QT interval. Psychosomatics 2013; 54(5): 502. https://www.ncbi.nlm.nih.gov/pubmed/24034531

2. Zhou SH, Wong S, Rautaharju PM, et al. Should the JT rather than the QT be used to detect prolongation of ventricular repolarization? An assessment in normal conduction and in ventricular conduction defects. J Electrocardiology 1992; 25 (Suppl): 131-6. https://www.ncbi.nlm.nih.gov/pubmed/1297679

Contributed by Jonathan Salik, MD, Mass General Hospital, Boston, MA

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Is the QTc interval an accurate reflection of myocardial repolarization time in ventricular conduction defects associated with a widened QRS complex?

Is bridging anticoagulation necessary perioperatively in patients with non-valvular atrial fibrillation (AF)?

FA Manian MD, MPH, , , Leave a comment

Until recently, there were no randomized-controlled trials (RCTs) available to help guide our decision.  A 2015 RCT, however, demonstrated that foregoing bridging anticoagulation was not inferior to bridging with low-molecular-weight heparin in patients with chronic or paroxysmal AF for the prevention of arterial thromboembolism and decreased the risk of major bleeding (1).  

It’s important to keep in mind the ineligibility criteria in this study before you consider not bridging perioperatively.  The following were listed as exclusion criteria in this study:

  • Mechanical valve
  • Stroke
  • Systemic embolism or transient ischemic attack within the previous 12 weeks
  • Major bleeding within the previous 6 weeks
  • Creatinine clearance < 30 ml/min
  • Platelet count < 100,000/ cubic ml
  • Planned cardiac, intracranial, or intraspinal surgery.                                                                                                                                     

Another important caveat of the BRIDGE study is that it included relatively few patients (<5%) with CHADS-2 score >4.

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Reference

  1. Douketis JD, Spyropoulos AC, Kaatz S, et al. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med 2015 (published June 22 at NEJM.org).
Is bridging anticoagulation necessary perioperatively in patients with non-valvular atrial fibrillation (AF)?