Cough reflex by ventricular premature contractions

Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study

Background

Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition.

Methods

We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors.

Findings

The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job.

Interpretation

Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors.

Funding

Wellcome Trust.

The effect of stimulation and unloading of baroreceptors on cough in experimental conditions

Cough, the main airway defensive process, is modulated by multiple sensory inputs from the respiratory system and outside of it. This modulation is one of the mechanisms that contributes to the sensitization of cough pathways at the peripheral and/or central level via neuroplasticity and it manifests most often as augmented coughing. Cardiorespiratory coupling is an important mechanism responsible for a match between oxygenation and cardiac output and bidirectional relationships exist between respiration and cardiovascular function. While the impact of cough with the robust swings of the intrathoracic pressure on haemodynamic parameters and heart electrophysiology are well characterized, little is known about the modulation of cough by haemodynamic parameters - mainly the blood pressure. Some circumstantial findings from older animal studies and more recent sophisticated analysis confirm that baroreceptor stimulation and unloading alters coughing evoked in experiments. Clinical relevance of such findings is not presently known.

Case Report: Premature Ventricular Beats-Induced Chronic Cough and Cough Syncope

Background: Chronic cough is a common complaint that in rare cases can be caused by premature ventricular beats (PVCs). Materials and Methods: In this report, we present the case of a healthy 44-year-old female who presented persistent cough and cough syncope that was attributed to PVCs. Results: The cough disappeared after radiofrequency ablation, and no recurrence of arrhythmia or cough was observed. Conclusion: PVCs should be considered a probable cause of chronic cough and cough syncope in differential diagnosis.

Cough as a Cause and Consequence of Heart Dysfunction - Current State of Art

The cough reflex is an airway defensive process that can be modulated by afferent inputs from organs located also out of the respiratory system. A bidirectional relationship between cough and heart dysfunctions are presented in the article, with the special insights into an arrhythmia-triggered cough. Albeit rare, cough induced by cardiac pathologies (mainly arrhythmias) seems to be an interesting and underestimated phenomenon. This condition is usually associated with the presence of abnormal heart rhythms and ceases with successful treatment of arrhythmia either by pharmacotherapy or by radiofrequency ablation of arrhythmogenic substrate. The two main hypotheses on cough-heart relationships - reflex and hemodynamic - are discussed in the review, including the authors' perspective based on the experiences with an arrhythmia-triggered cough.

Chronic cough in the elderly

Chronic cough is a multi-factorial syndrome commonly presenting as cough hypersensitivity in adult patients. It is a common medical condition in the communities but is more prevalent in older adults. Elderly patients (≥65 years) frequently suffer from multiple comorbidities, which may lead to more clinical heterogeneity in chronic cough and pose diagnostic and therapeutic challenges. Hyposensitivity in cough reflex, probably resulting from central nervous system illnesses, is another potential concern. Despite these complexities and challenges, elderly-specific issues have rarely been addressed in current clinical practice guidelines for chronic cough. Considering recent trends in global population aging, the burden of elderly chronic cough is expected to increase into the near future. This review aimed to respond to following clinical questions: (1) is chronic cough a more heterogeneous condition in the elderly compared to younger adults; and (2) are there additional considerations when choosing the diagnostic and therapeutic approaches to this condition in the elderly?

Severe, chronic cough caused by pulmonary arteriovenous malformations in a patient with hereditary haemorrhagic telangiectasia: case report

Background

Patients with pulmonary arteriovenous malformations usually complain of dyspnoea upon exertion, fatigue or migraine, or may be asymptomatic. We describe a patient with an unreported manifestation of a pulmonary arteriovenous malformation: a severe chronic cough.

Case presentation

A 51-year old Caucasian non-smoking female police officer presented with a chronic cough. She had been diagnosed with hereditary haemorrhagic telangiectasia in 1992. She complained of a severe, dry cough at the time of the diagnosis and a pulmonary arteriovenous malformation in the upper left lobe as demonstrated by CT of the chest. The fistula was occluded and the cough disappeared rapidly but resumed in 1994. Recanalisation of the fistula led to a new embolisation procedure, and the cough disappeared. Similar episodes occurred in 1998 and 2004, leading to embolisation of a fistula in the right lower lobe and reperfused fistula in the upper left lobe, respectively. The patient was referred to our research team in 2010 because of reappearance of her dry cough that was more pronounced during exercise and exposure to volatile irritants, and absent during the night. Despite extensive investigations, no cause was found other than reperfusion of the fistula in the left upper lobe. The malformation was not accessible to embolisation, leading us to recommend surgical excision of the malformation. A surgeon undertook atypical resection of the left upper lobe in 2012. The cough disappeared immediately after surgery and has not recurred.

Conclusion

Physicians caring for patients with pulmonary arteriovenous malformations should know that a severe, chronic cough can be caused by the malformation. A cough associated with a pulmonary arteriovenous malformation can be treated effectively by embolisation but may resume in cases of reperfusion of the malformation. In our case, the severity of the cough led to surgical excision because embolisation was not possible. The mechanism of action of this cough remains to be determined.

Chronic cough and tachycardia-induced cardiomyopathy in a patient with idiopathic frequent, monomorphic premature ventricular contractions

A 70-year-old woman presented with a 1-year history of dry cough. Extensive work-up ruled out common causes of chronic cough. She was found to have very frequent, monomorphic premature ventricular contractions (PVCs) and mild-to-moderate left ventricular systolic dysfunction. Propafenone 450 mg/day resulted in complete resolution of her cough and disappearance of PVCs within 24 hours of initiation. One month after the initiation of propafenone therapy, left ventricular ejection fraction normalized and her chronic cough resolved completely.

Diagnosis and management of premature ventricular complexes-associated chronic cough

BACKGROUND

Chronic cough frequently remains unexplained. Although various cardiac arrhythmias have already been reported as a cause of chronic cough, this phenomenon has not been evaluated prospectively. Therefore, we studied the incidence and management of cough associated with premature ventricular complexes (PVCs) in a population of patients with this condition.

METHODS

Patients without organic heart disease who had been referred for the management of symptomatic PVC were evaluated prospectively. PVC-associated cough was recognized if cough episodes occurred just after spontaneous or induced PVC or observed in an ECG or a multichannel recording system that included ECG. A differential diagnosis of cough was performed according to the guidelines on cough. Afterward, antiarrhythmic therapy was instituted to eliminate PVC and cough.

RESULTS

Of the 120 patients who were referred for the management of PVC, 10 had a chronic cough. After extensive workup for the cause of chronic cough, the cough was thought to be solely due to PVC in one patient, partially due to PVC plus another cause in five patients, and not due to PVC but to nonasthmatic eosinophilic bronchitis, gastroesophageal reflux disease, and chronic sinusitis in four patients. Patients with PVC-associated cough reported more severe perception of symptoms associated with arrhythmia than patients without cough (mean [+/- SD] visual analog scale score, 8.2 +/- 0.5 vs 5.7 +/- 1.6, respectively; p < 0.01). PVC-associated cough disappeared after antiarrhythmic treatment (radiofrequency ablation [n = 4], oral antiarrhythmic agent [n = 1]), or after spontaneous remission of PVC (n = 1).

CONCLUSIONS

PVC may be a cause of chronic cough. Interdisciplinary cooperation is warranted for the proper diagnosis and management of PVC-associated cough.

Intermittent claudication caused by frequent premature ventricular complexes: resolution after radiofrequency ablation

A case of a 55-year-old woman with psoriasis and long-lasting history of typical intermittent claudication associated with frequent premature ventricular complexes is reported. Atherosclerotic and nonarterial pathologic conditions were taken into consideration and were excluded. Applying 6-minute walk test and resting and peak-exercise pulsed Doppler ultrasonography, it was possible to prove a decrease in perfusion during exercise-persistent ventricular bigeminy. Rapid improvement in symptoms was observed after a single dose of propafenone; however, it led to a worsening of psoriasis. The patient was referred for radiofrequency ablation. Radiofrequency ablation in the right ventricular outflow tract resulted in complete abolition of premature ventricular complexes and intermittent claudication. The patient remained free of claudication and symptoms related to arrhythmia with an ability to walk more than 5 km, without stopping. Relief of symptoms may be achieved by antiarrhythmic treatment; however, side effects of antiarrhythmic drugs or their ineffectiveness should encourage the use of radiofrequency ablation.