A handful of cases of voluntary control of left bundle branch block (LBBB) have been described in the literature. We report the case of a middle-aged man who was found to have LBBB on baseline electrocardiogram (ECG) which disappeared on coughing and then reappeared with the same maneuver. Subsequent myocardial perfusion scan showed reduced count in the anteroseptal region likely attributed to LBBB. It is possible that the intermittent conduction changes may be due to the alteration in the vagal tone associated with cough as reflected in the change in the PR interval on the ECG

Faheem, osman

Hameed, Aamir

Khandwala, Kumail

Shahab, Hunaina

English

eCommons@AKU

eCommons@AKUSection of Cardiology Department of MedicineOctober 2018A Curious Case of Intermittent Left Bundle BranchBlock Associated with CoughHunaina ShahabAga Khan University, hunaina.shahab@aku.eduosman FaheemAga Khan UniversityKumail KhandwalaAga Khan UniversityAamir HameedAga Khan University, aamir.hameed@aku.eduFollow this and additional works at: https://ecommons.aku.edu/pakistan_fhs_mc_med_cardiolPart of the Cardiology CommonsRecommended CitationShahab, H., Faheem, o., Khandwala, K., Hameed, A. (2018). A Curious Case of Intermittent Left Bundle Branch Block Associatedwith Cough. Curēus., 10(10), e3520.Available at: https://ecommons.aku.edu/pakistan_fhs_mc_med_cardiol/108Received 10/17/2018 Review began 10/22/2018 Review ended 10/24/2018 Published 10/30/2018© Copyright 2018Shahab et al. This is an open accessarticle distributed under the terms ofthe Creative Commons AttributionLicense CC-BY 3.0., which permitsunrestricted use, distribution, andreproduction in any medium, providedthe original author and source arecredited.A Curious Case of Intermittent Left BundleBranch Block Associated with CoughHunaina Shahab  , Osman Faheem  , Kumail Khandwala  , Aamir H. Khan 1. Medicine, Aga Khan University Hospital, Karachi, PAK 2. Department of Radiology, The Aga KhanUniversity, Karachi, PAK Corresponding author: Aamir H. Khan, aamirhameedkhan@yahoo.com Disclosures can be found in Additional Information at the end of the articleAbstractA handful of cases of voluntary control of left bundle branch block (LBBB) have been describedin the literature. We report the case of a middle-aged man who was found to have LBBB onbaseline electrocardiogram (ECG) which disappeared on coughing and then reappeared with thesame maneuver. Subsequent myocardial perfusion scan showed reduced count in theanteroseptal region likely attributed to LBBB. It is possible that the intermittent conductionchanges may be due to the alteration in the vagal tone associated with cough as reflected in thechange in the PR interval on the ECG.Categories: CardiologyKeywords: left bundle-branch block (lbbb), cough, electrocardiogram (ecg), voluntary control of lbbbIntroductionEppinger and Rothberger in the 1900s showed that the section of the left bundle branchproduced a characteristic change in the electrocardiogram (ECG) which was later known to bethe left bundle branch block (LBBB) [1]. The prevalence of LBBB is 1.1% [2]. In 1979, theFramingham study prospectively showed that the people who developed LBBB were mostlythose with prior hypertension, coronary artery disease, or cardiac dilatation and within adecade, 50% of these people died of cardiovascular causes [3]. The mortality risk associatedwith LBBB prompts further investigation ranging from noninvasive to invasive in selectedcases [4-5]. There is very little literature on the voluntary control of LBBB; however, wedescribe the case of a middle-aged man with a history of atypical chest pain and cough whopresented with LBBB which reverted to narrow complex on coughing and back to LBBB on thesame maneuver.Case PresentationA 57-year-old man, who was diabetic, hypertensive and had a family history of ischemic heartdisease, presented to the cardiology clinic at the Aga Khan University Hospital, Karachi,Pakistan. He had a history of retrosternal chest burning after meals and occasional chestheaviness at rest with no relationship to exertion. He had been complaining of a dry cough forthe past four to five days. He was functional class I. On clinical examination, he had a bloodpressure of 138/84 mmHg and a heart rate of 76 beats per minute, with an oxygen saturation of98% on room air. Cardiac auscultation revealed S1 and S2 with no added heart sounds. Chestexamination revealed normal vesicular breathing. Rest of the systemic examination was alsowithin normal limits.1 1 2 1 Open Access CaseReport  DOI: 10.7759/cureus.3520How to cite this articleShahab H, Faheem O, Khandwala K, et al. (October 30, 2018) A Curious Case of Intermittent Left BundleBranch Block Associated with Cough. Cureus 10(10): e3520. DOI 10.7759/cureus.3520Baseline ECG showed normal sinus rhythm with LBBB. Blood workup included complete bloodcount, creatinine, and electrolytes which were within normal ranges. Two sets of troponin Iconducted from the clinic were negative. He was then referred for a myocardial perfusion scanwith dipyradimole for ischemia assessment. Baseline ECG is shown in Figure 1A-1B. As per ourinstitutional protocol, same day rest single photon emission computed tomography (SPECT)imaging was obtained with 760 MBq of intravenous (IV) Tc-99m tetrofosmin.FIGURE 1: Baseline electrocardiogram of the patient.(A) Normal sinus rhythm at 83 beats per minute with a normal axis and a left bundle branch block;(B) Zoomed image of leads V4 to V6 showing the PR interval of 200 milliseconds.At the start of the stress part of the test, the patient had a bout of dry cough. The ECG monitordocumented a conversion of the LBBB to narrow complex after the patient coughed as shown inFigure 2A-2B.2018 Shahab et al. Cureus 10(10): e3520. DOI 10.7759/cureus.3520 2 of 7FIGURE 2: Electrocardiogram (ECG) at the start of the stresspart of the myocardial perfusion scan before injecting IVdipyradimole.(A) It shows the conversion of the baseline left bundle branch block to narrow QRS complexes aftera bout of cough as depicted by the artifact in the ECG; (B) Zoomed image of the ECG which showsthe limb leads I, II, III, augmented vector right (AVR), augmented vector left (AVL), and augmentedvector foot (AVF) showing the subtle decrease in PR interval from 200 milliseconds before thecough with wide QRS complexes to 180 milliseconds afterward with narrow QRS complexes.He was then asked to cough again which showed conversion of narrow complex rhythm back toLBBB as shown in Figure 3A-3B.2018 Shahab et al. Cureus 10(10): e3520. DOI 10.7759/cureus.3520 3 of 7FIGURE 3: Electrocardiogram (ECG) at the start of the stresspart of the myocardial perfusion scan before injecting IVdipyradimole.(A) It shows the conversion of the narrow QRS complexes to left bundle branch block after thepatient was asked to cough again as depicted by the artifact in the ECG; (B) Zoomed image of theECG which shows the precordial leads V1 to V6 showing the subtle increase in PR interval from180 milliseconds before the cough with narrow QRS complexes to 200 milliseconds afterward withwide QRS complexes.Then 0.56 mg/kg of IV dipyradimole was injected followed by IV 270 MBq of Tc-99mtetrofosmin for stress SPECT imaging. IV aminophylline was given as per the protocol ofmyocardial perfusion imaging followed at our center. Neither the IV medications nor theinjection of the isotope changed the LBBB to narrow complex rhythm. The patient was thensent for myocardial perfusion imaging. The myocardial perfusion scan was found to have aslightly reduced count in the anteroseptal region likely due to the LBBB as shown in Figure 4.The gated images revealed a calculated ejection fraction of 60% in stress with anteroseptalhypokinesis (not shown).2018 Shahab et al. Cureus 10(10): e3520. DOI 10.7759/cureus.3520 4 of 7FIGURE 4: Myocardial perfusion imaging.Myocardial perfusion scan of the patient in warm metal which shows reduced count in theanteroseptal region which is likely attributed to the left bundle branch block on theelectrocardiogram.He was started on oral antacids and oral proton pump inhibitors. It was decided to follow thepatient for any recurrent symptoms or development of high-risk features which wouldnecessitate a coronary angiogram. On two months follow-up, the patient remainsasymptomatic and can easily walk more than four flights of stairs with no complaints. DiscussionAn inter-ventricular conduction defect that returns to normal, whether temporary or otherwise,is termed as a transient bundle branch block; whereas the presence of intermittent conductiondefect in a single electrocardiogram alternating with normal, or pre-excitation complexes istermed as an intermittent bundle branch block [6-7].In 1931, three cases of bundle branch block transitioning to normal conduction were describedin response to respiratory maneuvers, partially attributed to vagal effect [8]. A case seriespublished in 1964 reported five cases out of 167 patients with bundle branch block which wasintermittent and could be induced with simple maneuvers. Four out of those five patients hadunderlying ischemic heart disease [9].Another case of LBBB reported in 2012 was of an elderly man with laughter-induced LBBB, whowas found to have a partially reversible inferolateral defect with inducible peri-infarctischemia. He subsequently had triple vessel disease on coronary angiogram. Successfulpercutaneous intervention to the left circumflex artery was done after which the LBBB was notinduced by laughing, raising the likelihood that the mechanism of LBBB was ischemia-driven [10]. To the best of our knowledge, there is no prior documented case of control of LBBBwith coughing.2018 Shahab et al. Cureus 10(10): e3520. DOI 10.7759/cureus.3520 5 of 7In our case, the patient had a perfusion defect that is most likely attributed to the presence ofthe LBBB rather than ischemia. We believe that coughing changes the vagal tone asdemonstrated by a change in the PR interval on the ECG which contributes towards theintermittent appearance and disappearance of LBBB similar to the mechanism reported byHerrmann and Ashman [8]. As majority of the cases on voluntary induction of LBBB in ourliterature review had underlying ischemic heart disease, we decided to follow-up the patient forany repeated symptoms or development of any high-risk features warranting a coronaryangiogram. Till date, the patient remains asymptomatic on proton pump inhibitors. ConclusionsMost patients with LBBB are those with prior hypertension, coronary artery disease, or cardiacdilatation. However, our case adds to the handful of cases of voluntary induction of LBBB inliterature. It is possible that coughing alters the vagal tone of the body, leading to theconversion of LBBB to narrow complex rhythm and vice versa. Literature review also revealsthat mostly voluntary control of LBBB is associated with underlying ischemia. This warrants afollow-up on such patients for the development of typical symptoms or high-risk features.Additional InformationDisclosuresHuman subjects: Consent was obtained by all participants in this study. Conflicts of interest:In compliance with the ICMJE uniform disclosure form, all authors declare the following:Payment/services info: All authors have declared that no financial support was received fromany organization for the submitted work. Financial relationships: All authors have declaredthat they have no financial relationships at present or within the previous three years with anyorganizations that might have an interest in the submitted work. Other relationships: Allauthors have declared that there are no other relationships or activities that could appear tohave influenced the submitted work.AcknowledgementsWe would like to thank Mr. Shafqat Khan, Mr. Babar Nagher (Charge Technologists, NuclearCardiology, Cardiopulmonary Department) and Mr. Zaheer Ali Shah (Registered Nurse,Cardiopulmonary Department) for their help in providing data for the case report.References1. Eppinger H, Rothberger CJ: Zur analyse des elektrokardiogramms. Wien Klin Wochenschr.1909. 22:1091-1098.2. Zhang ZM, Rautaharju PM, Soliman EZ, et al.: Mortality risk associated with bundle branchblocks and related repolarization abnormalities (from the Women's Health Initiative [WHI]).Am J Cardiol. 2012, 110:1489-1495. 10.1016/j.amjcard.2012.06.0603. Schneider JF, Thomas HE, Kreger BE, McNamara PM, Kannel WB: Newly acquired left bundle-branch block: the Framingham study. Ann Intern Med. 1979, 90:303-310. 10.7326/0003-4819-90-3-3034. Corrado D, Pelliccia A, Bjørnstad HH, et al.: Cardiovascular pre-participation screening ofyoung competitive athletes for prevention of sudden death: proposal for a common Europeanprotocol: Consensus Statement of the Study Group of Sport Cardiology of the Working Groupof Cardiac Rehabilitation and Exercise Physiology and the Working Group of Myocardial andPericardial Diseases of the European Society of Cardiology. Eur Heart J. 2005, 26:516-524.10.1093/eurheartj/ehi1085. Francia P, Balla C, Paneni F, Volpe M: Left bundle‐branch block -- pathophysiology, prognosis,and clinical management. Clin Cardiol. 2007, 30:110-115. 10.1002/clc.200346. Bauer GE: Transient bundle-branch block. Circulation. 1964, 29:730-738.2018 Shahab et al. Cureus 10(10): e3520. DOI 10.7759/cureus.3520 6 of 710.1161/01.CIR.29.5.7307. Bauer GE: Wolff-Parkinson-White complexes alternating with left bundle branch block . AmHeart J. 1957, 54:452-457. 10.1016/0002-8703(57)90135-78. Herrmann G, Ashman R: Partial bundle-branch block: a theoretical consideration of transientnormal intraventricular conduction in the presence of apparently complete bundle branchblock. Am Heart J. 1931, 6:375-403. 10.1016/S0002-8703(31)90303-79. Bauer GE: Bundle-branch block under voluntary control. Br Heart J. 1964, 26:167-179.10.1136/hrt.26.2.16710. Chow GV, Desai D, Spragg DD, Zakaria S: Laughter‐induced left bundle branch block . JCardiovasc Electrophysiol. 2012, 23:1136-1138. 10.1111/j.1540-8167.2012.02296.x2018 Shahab et al. Cureus 10(10): e3520. DOI 10.7759/cureus.3520 7 of 7

A Curious Case of Intermittent Left Bundle Branch Block Associated with Cough

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A Curious Case of Intermittent Left Bundle Branch Block Associated with Cough

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