• Optimal electrocardiographic limb lead set for rapid emphysema screening

      Bajaj, Rishi; Chhabra, Lovely; Basheer, Zainab; Spodick, David H. (2013-01-18)
      BACKGROUND: Pulmonary emphysema of any etiology has been shown to be strongly and quasidiagnostically associated with a vertical frontal P wave axis. A vertical P wave axis (>60 degrees) during sinus rhythm can be easily determined by a P wave in lead III greater than the P wave in lead I (bipolar lead set) or a dominantly negative P wave in aVL (unipolar lead set). The purpose of this investigation was to determine which set of limb leads may be better for identifying the vertical P vector of emphysema in adults. METHODS: Unselected consecutive electrocardiograms from 100 patients with a diagnosis of emphysema were analyzed to determine the P wave axis. Patients aged younger than 45 years, those not in sinus rhythm, and those with poor quality tracings were excluded. The electrocardiographic data were divided into three categories depending on the frontal P wave axis, ie, >60 degrees, 60 degrees, ordegrees, by each criterion (P amplitude lead III > lead I and a negative P wave in aVL). RESULTS: Sixty-six percent of patients had a P wave axis > 60 degrees based on aVL, and 88% of patients had a P wave axis > 60 degrees based on the P wave in lead III being greater than in lead I. CONCLUSION: A P wave in lead III greater than that in lead I is a more sensitive marker than a negative P wave in aVL for diagnosing emphysema and is recommended for rapid routine screening.
    • P-wave indices in patients with pulmonary emphysema: do P-terminal force and interatrial block have confounding effects

      Chhabra, Lovely; Chaubey, Vinod; Kothagundla, Chandrasekhar; Bajaj, Rishi; Kaul, Sudesh; Spodick, David H. (2013-05-14)
      INTRODUCTION: Pulmonary emphysema causes several electrocardiogram changes, and one of the most common and well known is on the frontal P-wave axis. P-axis verticalization (P-axis > 60 degrees ) serves as a quasidiagnostic indicator of emphysema. The correlation of P-axis verticalization with the radiological severity of emphysema and severity of chronic obstructive lung function have been previously investigated and well described in the literature. However, the correlation of P-axis verticalization in emphysema with other P-indices like P-terminal force in V1 (Ptf), amplitude of initial positive component of P-waves in V1 (i-PV1), and interatrial block (IAB) have not been well studied. Our current study was undertaken to investigate the effects of emphysema on these P-wave indices in correlation with the verticalization of the P-vector. MATERIALS AND METHODS: Unselected, routinely recorded electrocardiograms of 170 hospitalized emphysema patients were studied. Significant Ptf (s-Ptf) was considered >/=40 mm.ms and was divided into two types based on the morphology of P-waves in V1: either a totally negative (-) P wave in V1 or a biphasic (+/-) P wave in V1. RESULTS: s-Ptf correlated better with vertical P-vectors than nonvertical P-vectors (P = 0.03). s-Ptf also significantly correlated with IAB (P = 0.001); however, IAB and P-vector verticalization did not appear to have any significant correlation (P = 0.23). There was a very weak correlation between i-PV1 and frontal P-vector (r = 0.15; P = 0.047); however, no significant correlation was found between i-PV1 and P-amplitude in lead III (r = 0.07; P = 0.36). CONCLUSION: We conclude that increased P-tf in emphysema may be due to downward right atrial position caused by right atrial displacement, and thus the common assumption that increased P-tf implies left atrial enlargement should be made with caution in patients with emphysema. Also, the lack of strong correlation between i-PV1 and P-amplitude in lead III or vertical P-vector may suggest the predominant role of downward right atrial distortion rather than right atrial enlargement in causing vertical P-vector in emphysema.
    • PAD2-mediated citrullination of Fibulin-5 promotes elastogenesis

      Sun, Bo; Tomita, Beverly; Salinger, Ari J.; Tilvawala, Ronak; Li, Ling; Hakami, Hana; Liu, Tao; Tsoyi, Konstantin; Rosas, Ivan O.; Reinhardt, Dieter P.; et al. (2021-08-01)
      The formation of elastic fibers is active only in the perinatal period. How elastogenesis is developmentally regulated is not fully understood. Citrullination is a unique form of post-translational modification catalyzed by peptidylarginine deiminases (PADs), including PAD1-4. Its physiological role is largely unknown. By using an unbiased proteomic approach of lung tissues, we discovered that FBLN5 and LTBP4, two key elastogenic proteins, were temporally modified in mouse and human lungs. We further demonstrated that PAD2 citrullinated FBLN5 preferentially in young lungs compared to adult lungs. Genetic ablation of PAD2 resulted in attenuated elastogenesis in vitro and age-dependent emphysema in vivo. Mechanistically, citrullination protected FBLN5 from proteolysis and subsequent inactivation of its elastogenic activity. Furthermore, citrullinated but not native FBLN5 partially rescued in vitro elastogenesis in the absence of PAD activity. Our data uncover a novel function of citrullination, namely promoting elastogenesis, and provide additional insights to how elastogenesis is regulated.
    • Pathophysiology of Alpha-1 Antitrypsin Lung Disease

      Kalfopoulos, Michael; Wetmore, Kaitlyn; Elmallah, Mai K. (2017-07-28)
      Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by low serum levels of alpha-1 antitrypsin (AAT). Loss of AAT disrupts the protease-antiprotease balance in the lungs, allowing proteases, specifically neutrophil elastase, to act uninhibited and destroy lung matrix and alveolar structures. Destruction of these lung structures classically leads to an increased risk of developing emphysema and chronic obstructive pulmonary disease (COPD), especially in individuals with a smoking history. It is estimated that 3.4 million people worldwide have AATD. However, AATD is considered to be significantly underdiagnosed and underrecognized by clinicians. Contributing factors to the diagnostic delay of approximately 5.6 years are: inadequate awareness by healthcare providers, failure to implement recommendations from the American Thoracic Society/European Respiratory Society, and the belief that AATD testing is not warranted. Diagnosis can be attained using qualitative or quantitative laboratory testing. The only FDA approved treatment for AATD is augmentation therapy, although classically symptoms have been treated similarly to those of COPD. Future goals of AATD treatment are to use gene therapy using vector systems to produce therapeutic levels of AAT in the lungs without causing a systemic inflammatory response.
    • Therapeutics: Gene Therapy for Alpha-1 Antitrypsin Deficiency

      Gruntman, Alisha; Flotte, Terence R. (2017-07-28)
      This review seeks to give an overview of alpha-1 antitrypsin deficiency, including the different disease phenotypes that it encompasses. We then describe the different therapeutic endeavors that have been undertaken to address these different phenotypes. Lastly we discuss future potential therapeutics, such as genome editing, and how they may play a role in treating alpha-1 antitrypsin deficiency.