PubMed Health⌕ Search

Biomedical subjects

M Herrera Carranza

Publications and source records attributed to M Herrera Carranza.

8 recordsLinked to original sources
PubMed2006

[Cardiac resynchronization through a persistent left superior vena cava].

Cardiac resynchronization therapy is effective in the treatment of patients with severe heart failure and intraventricular dysynchrony. However, we are sometimes faced with the unexpected presence of a persistent left superior vena cava. We report the case of a patient with dilated cardiomyopathy and left ventricular dysynchrony in which we implanted a resynchronization pacemaker exclusively through a persistent left superior vena cava that did not communicate with the right vena cava.

Aged↗
PubMed2001

[Adaptation parameters in non-invasive mechanical ventilation. Experimental comparative study].

OBJECTIVE: To evaluate response to pressure and flow triggering in an experimental model of the normal, obstructive and restrictive lung with six non-invasive mechanical ventilation units: Vintil+ (VP), Respironics STD20 (RR), Puritan Bennet 335 (PB), Quantum (QT), DP90 (DP) and Sullivan II ST (SV). METHOD: Analog signals of volume, pressure and flow from a lung simulator were recorded by a Mingograph 34 polygraph. Positive inspiratory pressure (PIP) was 12 cmH2O, respiratory rate was 17 cycles/min, end expiratory pressure (PEEP) was 4 cmH2O, and inspiratory effort (P0.1) was 4 cmH2O. Parameters calculated were negative trigger pressure, trigger time (or the flow wave delay in triggering), and the percentage of peak inspiratory flow at which a change to exhalation or cycle phase. RESULTS: The RR and PB units had the best trigger response with pressure triggering below -1 cmH2O and trigger times less than 100 ms. VP proved to have the poorest response. The cycle of the RR agreed most closely with the standard (5-25% of peak inspiratory flow), whereas change to exhalation occurred with the other units with zero flow (in all patterns with DP90, and in restrictive patterns with PB and VP) or greater than 50% of peak inspiratory flow (in all models with QT). Analysis of pressure curves showed great differences in slope, plateau and depressurization. CONCLUSIONS: The RR unit proved to have the most homogeneous behavior for all the phase parameters studied as being the ones that most influence a patient's adaptation to a ventilator.

Models, Anatomic↗
PubMed2001

[Permanent pacing of the bundle of His after radiofrequency atrioventricular node ablation in patients with suprahisian conduction disturbances].

INTRODUCTION AND OBJECTIVES: The asynchronic contraction of the left ventricle due to left bundle branch block or right ventricular pacing is inferior from a hemodynamic point of view to the synchronic contraction through the conduction system. Several authors have reported some cases of pump failure and deterioration of mitral regurgitation after AV nodal ablation. Alternative sites of pacing such as the right ventricular outflow tract pacing have been proposed in order to avoid these complications. Direct His bundle pacing might be a new alternative for permanent pacing, however, it has not been extensively evaluated in humans yet. Our aim is to prove the feasibility of permanent His pacing in terms of stability, thresholds and pump function. PATIENTS AND METHOD POPULATION: patients without structural heart disease, selected for AV nodal ablation due to uncontrolled paroxysmal atrial fibrillation, or for pacemaker implantation due to supraHis conduction disturbance, with normal conduction system. An active fixation permanent lead was placed in His position using an steering guidewire and a diagnostic catheter as an anatomical reference. We also implanted a lead in the right atrial appendage and both were connected to a DDDR generator. Pacing thresholds and ecocardiographic ventricular function parameters were evaluated (ejection fraction, cavity size, mitral regurgitation). RESULTS: 12 patients met the inclusion criteria. Successful His pacing was achieved in 8 out of 12 cases (66%) with acceptable thresholds at implantation (1.24 +/- 0.13 volts at 0.5 ms) and during follow up at 3 months (1.31 +/- 0.20 volts at 0.5 ms). Neither a significant change in the ecocardiographic parameters not a deterioration in the clinical status caused by ablation or stimulation was evidenced. CONCLUSION: The His bundle may be the site of choice for long term pacing in patients with AV block and normal infraHis conduction system.

Atrial Fibrillation↗
PubMed1981

[Continuous perfusion of low doses of insulin in severe diabetic decompensation (author's transl)].

Twenty one episodes of severe uncontrolled diabetes, most of them with ketoacidosis, were treated at a Medical Intensive Care Unit with fluid and electrolyte replacement and continuous perfusion of low doses of insulin. The overall results of this therapeutic approach were a progressive and gradual return to normality of all biochemical parameters with a fall of serum glucose levels and no hypoglycemic or hypokalemic accidents. Based on this study and on a review of the literature, an updated protocol for therapy of diabetic ketoacidosis is proposed.

Adolescent↗
PubMed1979

[Postoperative care in portal hypertension surgery (author's transl)].

The postoperative courses of 26 patients admitted to an Intensive Care Unit after different types of surgery on their portal tree are studied. All were diagnosed as having portal hypertension secondary to chronic liver disease and had presented one or more episodes of bleeding. Those complications of greater risk with an important early mortality rate are: 1) recurrence of the gastrointestinal hemorrhage, independently of the type of lesion which originates it; 2) recurrence of ascites because these patients more often develop dehiscence of the abdominal wall, serious dilutional hyponatremia and severe functional renal insufficiency; 3) acute renal failure, both functional or caused by an organic tubulo-interstitial nephropathy; 4) peritonitis; 5) persistent hepatolytic episode; 6) hyperdynamic heart failure; and 7) re-operations in general, independently of the causes. The frequency of these complications and the greater or lesser seriousness of their development in the postoperative period are dependent on: 1) the age of the patient with a better prognosis for those under 50; 2) the histopathologic type of the hepatic lesion, with hepatic fibrosis having a more favourable evolution in comparison with cirrhosis; 3) the degree of decompensation of the hepatopathy immediately before the operation, evaluating signs of functional hepatic deficit, cytolysis and degree of portal hypertension. The greater the preoperative activity, the worse the postsurgical prognosis. 4) The elective or urgent character of the surgery. During the postoperative course of emergency surgery all types of complications may appear. The emergency operation which has effectively achieved the stopping of the esophageal bleeding has been the porto-azygos disconnection, which allows later a portosystemic shunt with a greater probability of success. 5) The type of anastomosis carried out. Radicular shunts were those which had a lower postoperative mortality rate and those which progressed better because of the small number of problems occurring in the early postoperative period.

Adult↗